Chemistry

"We’re calling it a ready and release plan. This allows us to move quickly to prevent oil price spikes and respond to international events"

"Sweet oil, the fragrance of the gods, mixed oil, pressed oil, aromatic oil, cedar oil for offerings are mine."

"Enki sets up for you the lustration rituals created in his abzu; Kusu establishes the lustration rituals created in their specific house -- the oven for oxen, sheep and bread beside the interior of the bathing chamber, those sacred lustration rituals beside the shrine! Kusu purifies the oil for the house. It is placed in readiness [...] to ensure the sacred lustration rituals are not neglected, from the majestic marshes, the vast, sacred bathing chamber, this destiny emerges: the E-kic-nu-jal, with its majestic, sacred dais, perfects the great, majestic divine powers of heaven and earth. You bathe on the majestic banks by the sacred bathing chamber; you put mountain oil on your sacred body; O Nanna, you are placed upon your majestic dais -- wrapped in majestic linen, with raised head, shining horns and the pectoral of lordship! With the majestic oil of the sacred body, the oil of lordship, oil from your great treasury, lord Ningublaga consecrates the hands on his lapis-lazuli quay, the majestic quay, the sacred quay. But from Eridug the stag of the abzu Enki purifies the oil for those hands. So that you should place sacred hands upon your offering table in the banqueting hall, the great place, your steward Kusu -- she who purifies hands and cleanses hands -- consecrates the hands. But from Eridug the stag of the abzu purifies the oil for those hands."

"[the blockade puts emergency access at risk for more than 500 workers, and threatens] good faith commitments made between the Office of the Wet’suwet’en and the Province of B.C. to develop a new relationship based on respect"

"With the continued deterioration of weather conditions in the region in the coming days, Trans Mountain is closely monitoring the situation to ensure our crews can continue to progress safely"

""Anybody who follows the oil industry will tell you that it doesn't make any difference where the oil comes from," says Keith Crane, an energy expert at RAND Corp. Global oil markets are so intertwined, Crane says, that changes in any one part of the system can trigger effects elsewhere. He points out that the U.S. has imposed sanctions on Iran and therefore does not import its oil. But "if Iranian oil goes off the [world] market, it still affects the price in the United States," Crane says."

"To ask the question "What is oil?" is almost like asking "What is love?""

"What he has said is we'll continue to rely on Persian Gulf oil and if necessary sacrifice American lives in a fight for that oil. I don't think we ought to lose American lives fighting for someone else's oil. Because a war in the Middle East and the Persian Gulf - all we'll get is war and we won't get oil. And we'll lose a lot of American lives in the process."

"The world petroleum story is one of the most inhuman known to man: in it, elementary moral and social principles are jeered at. If powerful oil trusts no longer despoil and humiliate our country it is not because these predators have become human, but because we have won a hard-fought battle which has been going on since the beginning of the century."

"Our oil supply is secure, not because our government threatens to use force against those who would make it insecure, but because the world’s oil suppliers want to make money."

"I think Arctic drilling is insane. I think that countries around the world would be very well advised to put restrictions on drilling for oil in the Arctic ocean."

"As one approaches nearer to the country of the Cats, one finds heavy and thick water, which ignites like brandy, and boils up in bubbles of flame when fire is applied to it. It is, moreover, so oily, that all our Savages use it to anoint and grease their heads and their bodies."

"The place where we meet with it is called Ganos; where an officer worthy of credit [Joncaire] assured me that he had seen a fountain, the water of which is like oil and has the taste of iron. He said also that a little further there is another fountain exactly like it, and that the savages make use of its waters to appease all manner of pains."

"In 1991, Landsat captured the devastating environmental consequences of war. As Iraqi forces withdrew from Kuwait, they set fire to over 650 oil wells and damaged almost 75 more, which then spewed crude oil across the desert and into the Persian Gulf. Fires burned for ten months. According to a 2009 study published in Disaster Prevention and Management, firefighting crews from ten countries, part of a response team that comprised approximately 11,450 workers from 38 countries, used familiar and also never-before-tested technologies to put out the fires. When the last one was extinguished in November, about 300 lakes of oil remained, as well as a layer of soot and oil that fell out of the sky and mixed with sand and gravel to form 'tarcrete' across 5 percent of Kuwait's landscape."

"An estimated one to 1.5 billion barrels of oil were released into the environment. After most burned, 25 to 40 million barrels ended up spread across the desert and 11 million barrels in the Persian Gulf, according to a 2012 paper published in Remote Sensing of Environment. For comparison, the 2010 Deepwater Horizon spill into the Gulf of Mexico is estimated to have released nearly 5 million barrels of oil. Kuwait's landscape has recovered somewhat. Clean up efforts have removed 21 million barrels of oil from the desert, but an estimated 1 million barrels still remain."

"I’ve said many times that there isn’t a country in the world that would find billions of barrels of oil and leave it in the ground while there is a market for it."

"The most important strategic resource during the Cold War was oil. The first half of the twentieth century had seen its rise from a minor source of energy to becoming the substance that made modern states work. Armies depended on it for transport, and civilian economies depended on it for production. The Soviet Union became self-sufficient in 1954, so it was not competing with the West for access to foreign oil for its own sake. But the post-Stalin Moscow leaders knew how dependent US allies were on oil imports for their economic development. In western Europe dependence on oil for energy consumption increased from less than 10 percent in 1945 to over a third in 1960. In Japan the figures were even more striking: from 6 percent to 40. Eight-five percent of western Europe’s imports came from the Middle East already by 1950. For the United States, which up to 1970 relied primarily on its own production for domestic use, controlling access to Middle Eastern oil was therefore still of major strategic importance."

"Cooking is revelation and creation; and a woman can find special satisfaction in a successful cake or a flaky pastry, for not every one can do it: one must have the gift."

"Cookery is become an art, a noble science; cooks are gentlemen."

"And nearer as they came, a genial savour Of certain stews, and roast-meats, and pilaus, Things which in hungry mortals' eyes find favour."

"Yet smelt roast meat, beheld a huge fire shine, And cooks in motion with their clean arms bared."

"I seem to you cruel and too much addicted to gluttony, when I beat my cook for sending up a bad dinner. If that appears to you too trifling a cause, say for what cause you would have a cook flogged."

"A cook should double one sense have: for he Should taster for himself and master be."

"Oh, better no doubt is a dinner of herbs, When season'd by love, which no rancour disturbs And sweeten'd by all that is sweetest in life Than turbot, bisque, ortolans, eaten in strife! But if, out of humour, and hungry, alone A man should sit down to dinner, each one Of the dishes of which the cook chooses to spoil With a horrible mixture of garlic and oil, The chances are ten against one, I must own, He gets up as ill-tempered as when he sat down."

"'Tis burnt; and so is all the meat. What dogs are these! Where is the rascal cook? How durst you, villains, bring it from the dresser, And serve it thus to me that love it not?"

"He that will have a cake out of the wheat must needs tarry the grinding. Have I not tarried? Ay, the grinding: but you must tarry the bolting. Have I not tarried? Ay, the bolting: but you must tarry the leavening. Still have I tarried. Ay, to the leavening: but here's yet in the word "hereafter" the kneading, the making of the cake, the heating of the oven and the baking: nay, you must stay the cooling too, or you may chance to burn your lips."

"No one here will be surprised to hear me say that the Promethean fire which first raised humanity above the animal was the cooking fire."

"God sends meat, and the Devil sends cooks."

"Humans, unlike other animals, have a built-in need for supplemental energy, such as firewood, or fossil fuel energy. Over one million years ago, pre-humans figured out how to cook part of their food. Because of this cooked food, their jaws and digestive apparatus could shrink in size. The improved food supply allowed their brains to improve in complexity. Also, cooked food greatly reduced the time required for chewing, allowing more time for toolmaking and crafts. Heat is also important for killing pathogens in water."

"Every investigation which is guided by principles of nature fixes its ultimate aim entirely on gratifying the stomach."

"Great pity were it if this beneficence of Providence should be marr'd in the ordering, so as to justly merit the Reflection of the old proverb, that though God sends us meat, yet the D— does cooks."

"Hallo! A great deal of steam! the pudding was out of the copper. A smell like a washing-day! That was the cloth. A smell like an eating-house and a pastrycook's next door to each other, with a laundress's next door to that. That was the pudding."

"Ever a glutton, at another's cost, But in whose kitchen dwells perpetual frost."

"Heaven sends us good meat, but the devil sends us cooks."

"Poure faire un civet, prenez un lièvre."

"Digestion, much like Love and Wine, no trifling will brook: His cook once spoiled the dinner of an Emperor of men; The dinner spoiled the temper of his Majesty, and then The Emperor made history—and no one blamed the cook."

"Of herbs, and other country messes, Which the neat-handed Phillis dresses."

"The vulgar boil, the learned roast, an egg."

"I never strove to rule the roast, She ne'er refus'd to pledge my toast."

"A crier of green sauce."

"He ruleth all the roste With bragging and with boste."

"The waste of many good materials, the vexation that frequently attends such mismanagements, and the curses not unfrequently bestowed on cooks with the usual reflection, that whereas God sends good meat, the devil sends cooks."

"Let onion atoms lurk within the bowl, And, half-suspected, animate the whole."

"Velocius (or citius) quam asparagi coquantur."

"This Bouillabaisse a noble dish is— A sort of soup or broth, or brew, Or hotchpotch of all sorts of fishes, That Greenwich never could outdo; Green herbs, red peppers, mussels, saffron, Soles, onions, garlic, roach, and dace; All these you eat at Terre's tavern, In that one dish of Bouillabaisse."

"Very astonishing indeed! strange thing!" (Turning the Dumpling round, rejoined the King), "'Tis most extraordinary, then, all this is; It beats Penetti's conjuring all to pieces; Strange I should never of a Dumpling dream! But, Goody, tell me where, where, where's the Seam?" "Sire, there's no Seam," quoth she; "I never knew That folks did Apple-Dumplings sew." "No!" cried the staring Monarch with a grin; "How, how the devil got the Apple in?"

"The matter lies before the eyes of all; everybody sees it, touches it, loves it, but knows it not. It is glorious and vile, precious and of small account, and is found everywhere... But, to be brief, our Matter has as many names as there are things in this world; that is why the foolish know it not."

"[A]n art without principles, the beginning of which was deceit, the progress delusion, and the end poverty."

"Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost. That is alchemy's first law of Equivalent Exchange. In those days, we really believed that to be the world's one, and only truth."

"The Hindus do not pay particular attention to alchemy, but no nation is entirely free from it, and one nation has more bias for it than another, which must not be construed as proving intelligence or ignorance; for we find that many intelligent people are entirely given to alchemy, whilst ignorant people ridicule the art and its adepts."

"[E]very relation must be considered as suspicious, which depends in any degree upon religion, ... and ... everything that is to be found in the writers of natural magic or alchemy, or such authors, who seem, all of them, to have an unconquerable appetite for falsehood and fable."

"Alchemy may be compared to the man who told his sons that he had left them gold, buried somewhere in his vineyard; while they by digging found no gold, but by turning up the mould about the roots of the vines procured a plentiful vintage. So the search and endeavours to make gold have brought many useful inventions to light."

"Azoth is the essence of life! We alchemists have the ability to convert it into power! We can live forever! Your Azoth, Fiona, belongs to me! Come to me, Fiona. I will now extract the Azoth latent in you, in order to realize the everlasting life of Aureolus Belli."

"[E]ach author seems to have aimed to write treatises intelligible only to himself, and we greatly doubt his success in even this respect."

"What a lovely afternoon On a cloudbusting kind of day. We took our own 'Mystery Tour' And got completely lost somewhere up in the hills. And we came up on a bee-keeper, And he said "Did you know they can change it all?" They got alchemy. They turn the roses into gold They turn the lilac into honey They're making love for the peaches. And they'll do it, Do it for you."

"And mark yon alchemist, with zodiac-spangled zone, Wrenching the mandrake root that fattens in the gloom."

"[T]he growth of a plant, a tree, or an animal is an alchemical process going on in the alchemical laboratory of nature, and performed by the great Alchemist, the power of God acting in nature."

"Subtle. No egg but differs from a chicken more Than metals in themselves. Surly. That cannot be. The egg's ordained by nature to that end And is a chicken in potentia. Subtle. The same we say of lead and other metals, Which would be gold if they had time. ...for 'twere absurd To think that nature in the earth bred gold Perfect in the instant; something went before. There must be remote matter."

"Everyone knows Newton as the great scientist. Few remember that he spent half his life muddling with alchemy, looking for the philosopher's stone. That was the pebble by the seashore he really wanted to find."

"If by fire Of sooty coal th' empiric alchymist Can turn, or holds it possible to turn, Metals of drossiest ore to perfect gold."

"Alchemy is an erotic science, involved in buried aspects of reality, aimed at purifying and transforming all being and matter."

"They can picture love affairs of chemicals and stars, a romance of stones, or the fertility of fire. Strange, fertile correspondences the alchemists sensed in unlikely orders of being. Between men and planets, plants and gestures, words and weather."

"Although Alchemy has now fallen into contempt, and is even considered a thing of the past, the physician should not be influenced by such judgements. For many arts, such as astronomy, philosophy , and others, are also in disrepute. I am directing you, physicians, to alchemy for the preparation of the magnalia, for the production of the mysteria, for the preparation of the arcana, for the separation of the pure from the impure, to the end that you may obtain a flawless, pure remedy, God-given, perfect, and of certain efficacy, acheiving the highest degree of virtue and power. For it is not God's design that the remedies should exist for us, ready-made, boiled and salted, but that we should boil them ourselves, and it pleases Him that we boil them and learn in the process, that we train ourselves in this art and are not idle on earth, but labour in daily toil. For it is we who must pray for our daily bread, and if He grants it to us, it is only through our labour, our skill and preparation."

"The starving chemist in his golden views Supremely blest."

"Alchemists knew the coiled serpent as Uboros. ...it represented the highest goal of their quest: the harmonious union of opposites, especially the masculine and the feminine sides of the personality. The motto that usually accompanied it was "From the One to the One.""

"You are an alchemist; make gold of that."

"It is necessary to deprive matter of its qualities in order to draw out its soul. ... Copper is like a man; it has a soul and a body; ...the soul is the most subtile part, ... that is to say, the tinctorial spirit. The body is the ponderable, material, terrestrial thing, endowed with a shadow. ... After a series of suitable treatments copper becomes without shadow and better than gold. ...The elements ... grow and are transmuted, because it is their qualities, not their substances, which are contrary."

"Transmutemini (inquit) transmute∣mini de lapidibus mortuis in Lapides vivos philosophicos."

"I had discovered, early in my researches, that their doctrine was no mere chemical fantasy, but a philosophy they applied to the world, to the elements, and to man himself."

"O, he sits high in all the people's hearts; And that which would appear offence in us, His countenance, like richest alchemy, Will change to virtue and to worthiness."

"To solemnize this day the glorious sun Stays in his course and plays the alchemist, Turning with splendour of his precious eye The meagre cloddy earth to glittering gold."

"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and vapour, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I were to change places with the Persian king."

"It is the study of the Chemists to liberate that unsensual truth from its fetters in things of sense, for through it the heavenly powers are persued with subtle understanding....Knowledge is the sure and undoubted resolution by experiment of all opinions concerning the truth....Experiment is manifest demonstration of the truth, and resolution the putting away of doubt. We cannot be resolved of any doubt save by experiment, and therefore is no better way to make it than on ourselves. Let us therefore verify what we have said above concerning the truth, beginning with ourselves. We have said that piety consists in knowledge of ourselves, and hence it is said that we make philosophical knowledge begin from this also. But no man can know himself unless he know what and not who he is, on whom he depends and whose he is (for by the law of truth no one belongs to himself, and to what end he was made. With this knowledge piety begins, which is concerned with two things, namely, with the Creator and the creature that is made like unto him. For it is impossible for the creature to know himself of himself, unless he first know his Creator....No one can better know the Creator, than the workman is known by his work."

"Chymistry is all New; there was no such thing known to the Generations of Old. This Spagyrick Art, which was set on foot by Paracelsus and Helmont, and by some other searching Heads, hath had Prodigious Additions made to it lately. The Alchymists Retort and Alembick never were furnish'd with such rare and excellent Secrets as they are now; the Laboratories and Furnaces never afforded the like Inventions. It is indeed a rough and violent way of Philosophizing, it is an hectoring as it were of Nature, it is puting her upon the Rack, and on the Fiery Trial, to make her confess what she never did before. And truly she hath made a very ample Confession and Discovery, whereby the knowledge of Natural Philosophy is much increas'd and imbellish'd, very Noble and Precious Medicaments (consisting of Oyls, Spirits, Tinctures, Salts, &c.) are produced, and the Healthfulness of Men's Bodies, and their Longævity are procured, and the Almighty Creator thereby Exalted and Honoured."

"For the alchemist is the baker in baking the bread, the vintner in making the wine, the weaver in weaving cloth. Thus, whatever arises out of nature for human use is brought to that condition ordained by nature by an alchemist."

"The physician's duty is to heal the sick, not enrich the apothecaries."

"My travels have developed me; no man becomes a master at home, nor finds his teacher behind the stove. Sicknesses wander here and there the whole length of the world. If a man wishes to understand them, he must wander too. A doctor must be an alchemist, he must see mother earth where the minerals grow. And as the mountains will not come to him, he must go to the mountains. It is indeed true that those who do not roam have greater possessions than those who do; those who sit behind the stove eat partridge, and those who follow after knowledge eat milkbroth. He who will serve the belly-- he will not follow after me."

"Luther is abundantly learned, therefore you hate him and me, but we are at least a match for you."

"I admonish you not to reject the method of experiment, but according as your power permits, to follow it without prejudice. For every experiment is like a weapon which must be used according to its peculiar power, as a spear to thrust, a club to strike, so also is it with experiments."

"I praise the chemical physicians, for they do not go about gorgeous in satins, silks, and velvets, silver daggers hanging at their sides, and white gloves on their hands, but they tend their work at the fire patiently day and night. They do not go promenading, but seek their recreation in laboratory. They thrust their fingers among the coals into dirt and rubbish and not into golden rings."

"the true use of chemistry is not to make gold but to prepare medicines."

"Its name [alchemy] will no doubt prevent its being acceptable to many; but why should wise people hate without cause that which some other wantonly misuse? Why hate blue because some clumsy painter uses it? Which would Caesar order to be crucified, the thief or the thing he had stolen? No science can be deservedly held in contempt by one who knows noting about it. Because you are ignorant of alchemy, you are ignorant of the mysteries of nature."

"We must trust to nothing but facts: These are presented to us by Nature, and cannot deceive. We ought, in every instance, to submit our reasoning to the test of experiment, and never to search for truth but by the natural road of experiment and observation."

"God does not justify man on the ground of human learning; attainments in chemistry, anatomy, geology, botany, astronomy, or skill in sculpture and painting, — these do not prepare a man to die."

"Like a chemist, Napoleon considered all Europe to be material for his experiments. But in due course, this material reacted against him."

"Chemistry is not a primitive science, like geometry or astronomy; it is constructed from the debris of a previous scientific formation; a formation half chimerical and half positive, itself founded on the treasure slowly amassed by the practical discoveries of metallurgy, medicine, industry, and domestic economy. It has to do with alchemy, which pretended to enrich its adepts by teaching them to manufacture gold and silver, to shield them from diseases by the preparation of the , and finally to obtain for them perfect felicity by identifying them with the soul of the world and the universal spirit."

"Every chemical combination is wholly and solely dependent on two opposing forces, positive and negative electricity, and every chemical compound must be composed of two parts combined by the agency of their electrochemical reaction, since there is no third force. Hence it follows that every compound body, whatever the number of its constituents, can be divided into two parts, one of which is positively and the other negatively electrical."

"A tidy laboratory means a lazy chemist."

"If we could determine the nature of substances burning at Mannheim, why should we not do the same with regard to the sun? ---But people would say we must have gone mad to dream of such a thing."

"Men are not allowed to think freely about chemistry and biology: why should they be allowed to think freely about political philosophy?"

"If a possible — nay, reasonable — variation in only one of the forces conditioning the human race, that of gravitation, could so modify our outward form, appearance, and proportions as to make us to all intents and purposes a different race of beings; if mere differences of size can cause some of the most simple facts in chemistry and physics to take so widely different a guise; if beings microscopically small and prodigiously large would simply as such be subject to the hallucinations I have pointed out, and to others I might enlarge upon, is it not possible that we, in turn, though occupying, as it seems to us, the golden mean, may also by the mere virtue of our size and weight fall into misinterpretations of phenomena from which we should escape were we or the globe we inhabit either larger or smaller, heavier or lighter? May not our boasted knowledge be simply conditioned by accidental environments, and thus be liable to a large element of subjectivity hitherto unsuspected and scarcely possible to eliminate?"

"Chemists do not usually stutter. It would be very awkward if they did, seeing that they have at times to get out such words as methylethylamylophenylium."

"Chemical analysis and synthesis go no farther than to the separation of particles one from another, and to their reunion. No new creation or destruction of matter is within the reach of chemical agency. We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence, as to create or destroy a particle of hydrogen.""

"Most of the substances belonging to our globe are constantly undergoing alterations in sensible quantities, and one variety of matter becomes, as it were, transmuted into another. Such changes, whether natural or artificial, whether slowly or rapidly performed, are called chemical; thus the gradual and almost imperceptible decay of the leaves and branches of a fallen tree exposed to the atmosphere, and the rapid combustion of wood in our fires, are both chemical operations. The object of chemical philosophy is to ascertain the causes of all phenomena of this kind, and to discover the laws by which they are governed. The ends of this branch of knowledge are the applications of natural substances to new uses, for increasing the comforts and enjoyments of man, and the demonstration of the order, harmony, and intelligent design of the system of the earth."

"It's chemistry, brother, chemistry! There's no help for it, your reverence, you must make way for chemistry."

"One of the most immediate consequences of the electrochemical theory is the necessity of regarding all chemical compounds as binary substances. It is necessary to discover in each of them the positive and negative constituents... No view was ever more fitted to retard the progress of organic chemistry. Where the theory of substitution and the theory of types assume similar molecules, in which some of the elements can be replaced by others without the edifice becoming modified either in form or outward behaviour, the electrochemical theory divides these same molecules, simply and solely, it may be said, in order to find in them two opposite groups, which it then supposes to be combined with each other in virtue of their mutual electrical activity... I have tried to show that in organic chemistry there exist types which are capable, without destruction, of undergoing the most singular transformations according to the nature of the elements."

"Chemistry, Madame Lefrancois....the composition of manures, the fermentation of liquids, the analysis of gases and the influence of miasmata- what, I put it to you, is all this, but chemistry pure and simple?"

"Reader! Imagine a school-boy who has outgrown his clothes. Imagine the repairs made on the vestments where the enlarged frame had burst the narrow limits of its inclosure. Imagine the additions made where the projecting limbs had fairly and far emerged beyond the confines of the garment. Imagine the boy still growing, and the clothes, mended all over, now more than ever in want of mending — such is chemistry, and such its nomenclature."

"We can no more have exact religious thinking without theology, than exact mensuration and astronomy without mathematics, or exact iron-making without chemistry,"

"Once you are there you'll be like a drop of water in a piece of rock crystal- your medium will dignify your commonness."

"It is a mistake to confound Alchemy with Chemistry. Modern Chemistry is a science which deals merely with the external forms in which the element of matter is manifesting itself. It never produces anything new. We may mix and compound and decompose two or more chemical bodies an unlimited number of times, and cause them to appear under various different forms, but at the end we will have no augmentation of substance, nor anything more than the combinations of the substances that have been employed at the beginning. Alchemy does not mix or compound anything, it causes that which already exists in a latent state to become active and grow. Alchemy is, therefore, more comparable to botany or agriculture than to Chemistry; and, in fact, the growth of a plant, a tree, or an animal is an alchemical process going on in the alchemical laboratory of nature, and performed by the great Alchemist, the power of God acting in nature."

"The most powerful influence exercised by the Arabs on general natural physics was that directed to the advances of chemistry; a science for which this race created a new era.(...) Besides making laudatory mention of that which we owe to the natural science of the Arabs in both the terrestrial and celestial spheres, we must likewise allude to their contributions in separate paths of intellectual development to the general mass of mathematical science."

"Chemistry, in its application to animals and vegetables. Endeavours jointly with physiology to enlighten us respecting the mysterious processes and sources of organic life."

"I wish to establish some sort of system not guided by chance but by some sort of definite and exact principle."

"As Mechanical Philosophy has a respect to those motions of the larger bodies of the universe which fall under the inspection of our senses, so Chemical Philosophy is the science which explains those motions which take place among the minute component parts of bodies, and which are known chiefly by the effects which they produce; in other words, its object is, "to ascertain the ingredients that enter into the composition of bodies—to examine the nature of these ingredients, the manner in which, and the laws by which, they combine, and the properties resulting from their combination." It may safely be asserted, that there is no branch of science in which the discoveries and improvements, during the last century, have been more numerous, or more important, than in this. Indeed, such has been their number, and their interesting nature, that to exhibit them in detail would be to fill volumes."

"Do you believe then that the sciences would ever have arisen and become great if there had not beforehand been magicians, alchemists, astrologers, and wizards who thirsted and hungered after... forbidden powers?"

"'I am happy', said M. Waldman, 'to have gained a disciple; and if your application equals your ability, I have no doubt of your success. Chemistry is that branch of natural philosophy in which the greatest improvements have been and may be made: it is on that account that I have made it my peculiar study'"

"In the four quarters of the globe, who reads an American book? Or goes to an American play? or looks at an American picture or statue? What does the world yet owe to American physicians or surgeons? What new substances have their chemists discovered? Or what old ones have they advanced? What new constellations have been discovered by the telescopes of Americans? Who drinks out of American glasses? Or eats from American plates? Or wears American coats or gowns? or sleeps in American blankets? Finally, under which of the old tyrannical governments of Europe is every sixth man a slave, whom his fellow-creatures may buy and sell and torture?"

"Chemistry, unlike other sciences, sprang originally from delusions and superstitions, and was at its commencement exactly on a par with magic and astrology."

"Cellular pathology is not an end if one cannot see any alteration in the cell. Chemistry brings the clarification of living processes nearer than does anatomy. Each anatomical change must have been preceded by a chemical one."

"At this time organic chemistry can drive one completely crazy. It seems to me like a primeval tropical jungle, full of the most remarkable things, an amazing thicket, without escape or end, into which one would not dare to enter."

"Never before has mankind had to face the possibility of extinction in all-out fusion bomb war, nor has it had occasion for hope of unexampled prosperity in the taming of that same fusion bomb. Either fate could result from a single branch of scientific advance. We are gaining the knowledge; science is giving us that. Now we need wisdom as well."

"It was a great achievement of the early chemists — with the crude experimental techniques available also with the ever-astonishing power of human reason (as potent then as now) — to discover this reduction of the world to its components, the chemical elements. Such reduction does not destroy its charm but adds understanding to sensation, and this understanding only deepens our delight."

"The important point is not the bigness of Avogadro's number but the bigness of Avogadro."

"The first difficulty that faced us was the identification of the forms seen on focusing the sight on gases. We could only proceed tentatively. Thus, a very common form in the air had a sort of dumb-bell shape (see Plate I); we examined this, comparing our rough sketches, and counted its atoms; these, divided by 18—the number of ultimate atoms in hydrogen—gave us 23.22 as atomic weight, and this offered the presumption that it was sodium. We then took various substances—common salt, etc.—in which we knew sodium was present, and found the dumb-bell form in all. In other cases, we took small fragments of metals, as iron, tin, zinc, silver, gold; in others, again, pieces of ore, mineral waters, etc., etc.... In all, 57 chemical elements were examined, out of the 78 recognized by modern chemistry. In addition to these, we found 3 chemical waifs: an unrecognized stranger between hydrogen and helium which we named occultum, for purposes of reference, and 2 varieties of one element, which we named kalon and meta-kalon, between xenon and osmium... Thus we have tabulated in all 65 chemical elements, or chemical atoms, completing three of Sir William Crookes' lemniscates, sufficient for some amount of generalization. (Chapter III. The Later Researches)"

"Here, for the first time, we find ourselves a little at issue with the accepted system of chemistry. Fluorine stands at the head of a group—called the inter-periodic—whereof the remaining members are (see Crookes' table, p. 28), manganese, iron, cobalt, nickel; ruthenium, rhodium, palladium; osmium, iridium, platinum. If we take all these as group V, we find that fluorine and manganese are violently forced into company with which they have hardly any points of relationship, and that they intrude into an otherwise very harmonious group of closely similar composition. (Chapter III. The Later Researches, part V.—The Bars Groups)"

"On the arid lands there will spring up industrial colonies without smoke and without smokestacks; forests of glass tubes will extend over the plains and glass buildings will rise everywhere; inside of these will take place the photochemical processes that hitherto have been the guarded secret of the plants, but that will have been mastered by human industry which will know how to make them bear even more abundant fruit than nature, for nature is not in a hurry and mankind is. And if in a distant future the supply of coal becomes completely exhausted, civilization will not be checked by that, for life and civilization will continue as long as the sun shines!"

"The nature of the chemical bond is the problem at the heart of all chemistry."

"We must not forget that when radium was discovered no one knew that it would prove useful in hospitals. The work was one of pure science. And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it. It must be done for itself, for the beauty of science, and then there is always the chance that a scientific discovery may become like the radium a benefit for humanity."

"At some point a particularly remarkable molecule was formed by accident. We will call it the Replicator. It may not necessarily have been the biggest or the most complex molecule around, but it had the extraordinary property of being able to create copies of itself."

"Within a certain kind of environment, an activity may be checked so that the only meaning which accrues is of its direct and tangible isolated outcome. One may cook, or hammer, or walk, and the resulting consequences may not take the mind any farther than the consequences of cooking, hammering, and walking in the literal — or physical — sense. But nevertheless the consequences of the act remain far-reaching. To walk involves a displacement and reaction of the resisting earth, whose thrill is felt wherever there is matter. It involves the structure of the limbs and the nervous system; the principles of mechanics. To cook is to utilize heat and moisture to change the chemical relations of food materials; it has a bearing upon the assimilation of food and the growth of the body. The utmost that the most learned men of science know in physics, chemistry, physiology is not enough to make all these consequences and connections perceptible. The task of education, once more, is to see to it that such activities are performed in such ways and under such conditions as render these conditions as perceptible as possible."

"The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known, and the difficulty is only that the exact application of these laws leads to equations much too complicated to be soluble. It therefore becomes desirable that approximate practical methods of applying quantum mechanics should be developed, which can lead to an explanation of the main features of complex atomic systems without too much computation."

"Modern warfare, we discovered, was to a far greater extent than ever before a conflict of chemists and manufacturers. Manpower, it is true, was indispensable, and generalship will always, whatever the conditions, have a vital part to play. But troops, however brave and well led, were powerless under modern conditions unless equipped with adequate and up-to-date artillery (with masses of explosive shell), machine-guns, aircraft and other supplies. Against enemy machine-gun posts and wire entanglements the most gallant and best-led men could only throw away their precious lives in successive waves of heroic martyrdom. Their costly sacrifice could avail nothing for the winning of victory."

"The alchemical tradition assumes that every physical art or science is a body of knowledge which exists only because it is ensouled by invisible powers and processes. Physical chemistry, as it is practiced in the modern world, is concerned principally with pharmaceutical or industrial research projects. It is confined within the boundaries of an all-pervading materialism, which binds labor to the advancement of physical objectives."

"The natural sciences are sometimes said to have no concern with values, nor to seek morality and goodness, and therefore belong to an inferior order of things. Counter-claims are made that they are the only living and dynamic studies. Both contentions are wrong"

"The Joker: You IDIOT! You made me. Remember? You dropped me into that vat of chemicals. That wasn't easy to get over, and don't think that I didn't try."

"Somehow, the practice of astronomy, physics, chemistry or biology normally fails to evoke the controversies over fundamentals that today seem endemic among, say, psychologists or sociologists. Attempting to discover the source of that difference led me to recognize the role in scientific research of what I have since called “paradigms.” These I take to be universally recognized scientific achievements that for a time provide model problems and solutions for a community of practitioners."

"For me chemistry represented an indefinite cloud of future potentialities which enveloped my life to come in black volutes torn by fiery flashes, like those which had hidden Mount Sinai. Like Moses, from that cloud I expected my law, the principle of order in me, around me, and in the world. I was fed up with books, which I still continued to gulp down with indiscreet voracity, and searched for a key to the highest truths; there must be a key, and I was certain that, owing to some monstrous conspiracy to my detriment and the world's, I would not get in school. In school they loaded with me with tons of notions that I diligently digested, but which did not warm the blood in my veins. I would watch the buds swell in spring, the mica glint in the granite, my own hands, and I would say to myself: "I will understand this, too, I will understand everything, but not the way they want me to. I will find a shortcut, I will make a lock-pick, I will push open the doors." It was enervating, nauseating, to listen to lectures on the problem of being and knowing, when everything around us was a mystery pressing to be revealed: the old wood of the benches, the sun's sphere beyond the windowpanes and the roofs, the vain flight of the pappus down in the June air. Would all the philosophers and all the armies of the world be able to construct this little fly? No, nor even understand it: this was a shame and an abomination, another road must be found."

"That conquering matter is to understand it, and understanding matter is necessary to understanding the universe and ourselves: and that therefore Mendeleev's Periodic Table, which just during those weeks we were laboriously learning to unravel, was poetry, loftier and more solemn than all the poetry we had swallowed down in liceo; and come to think of it, it even rhymed!"

"Having reached this point in life, what chemist, facing the Periodic Table or the monumental indices of Beilstein or Landolt, does not perceive scattered amoung them the sad tatters, or trophies, of his own professional past? He only has to leaf through any treatise and memories rise up in bunches: there is among us he who has tied his destiny, indelibly, to bromine or to propylene, or the -NCO group, or glutamic acid; and every chemistry student, faced by almost any treatise, should be aware that on one of those pages, perhaps in a single line, formula, or word, his future is written in indecipherable characters, which, however, will become clear "afterward": after success, error, or guilt, victory or defeat. Every no longer young chemist, turning again to the verhängnis voll page in that same treatise, is struck by love or disgust, delights or despairs."

"I could tell innumerable other stories and they would all be true: all literally true, in the nature of the transitions, in their order and data. The number of atoms is so great that one could always be found whose story coincides with any capriciously invented story."

"But we are still blind... blind and we don't have those tweezers we often dream of at night, the way a thirsty man dreams of springs, that would allow us to pick up a segment, hold it firm and straight, and paste it in the right direction on the segment that has already been assembled. If we had those tweezers (and it's possible that, one day, we will), we would have managed to create some wonderful things But for the present we don't have those tweezers, and when we come right down to it, we're bad riggers."

"Chemistry without catalysis would be a sword without a handle, a light without brilliance, a bell without sound."

"There is a narrowness of action, though not of intent, which characterizes university departments, and scientific publications and scientists in general: if it is too popular, it is somehow vulgar and wrong. You can't really speak to those people across the street. I live next to the chemists at MIT, but I never see them. I hardly know who they are, yet between physics and chemistry it is hard to know who should study what molecule. I myself am guilty. We form communities not based on the problems of science, but on quite other things. This is part of the general split between the intelligent member of the public and the scientist who speaks in narrow focus. But the great theoretical problems which I believe the world expects will somehow be solved by science, problems close to deep philosophical issues are the very problems that find the least expertise, the least degree of organization, the least institutional support in the scientific institutions of America or indeed of the world."

"Every chemical substance, whether natural or artificial, falls into one of two major categories, according to the spatial characteristic of its form. The distinction is between those substances that have a plane of symmetry and those that do not. The former belong to the mineral, the latter to the living world."

"We may, I believe, anticipate that the chemist of the future who is interested in the structure of proteins, nucleic acids, polysaccharides, and other complex substances with high molecular weight will come to rely upon a new structural chemistry, involving precise geometrical relationships among the atoms in the molecules and the rigorous application of the new structural principles, and that great progress will be made, through this technique, in the attack, by chemical methods, on the problems of biology and medicine."

"Just think of the differences today. A young person gets interested in chemistry and is given a chemical set. But it doesn't contain potassium cyanide. It doesn't even contain copper sulfate or anything else interesting because all the interesting chemicals are considered dangerous substances. Therefore, these budding young chemists don't get a chance to do anything engrossing with their chemistry sets. As I look back, I think it is pretty remarkable that Mr. Ziegler, this friend of the family, would have so easily turned over one-third of an ounce of potassium cyanide to me, an eleven-year-old boy."

"The Second Law of Thermodynamics states that all energy systems run down like a clock and never rewind themselves. But life not only 'runs up,' converting low energy sea-water, sunlight and air into high-energy chemicals, it keeps multiplying itself into more and better clocks that keep 'running up' faster and faster. Why, for example, should a group of simple, stable compounds of carbon, hydrogen, oxygen and nitrogen struggle for billions of years to organize themselves into a professor of chemistry? What's the motive? If we leave a chemistry professor out on a rock in the sun long enough the forces of nature will convert him into simple compounds of carbon, oxygen, hydrogen and nitrogen, calcium, phosphorus, and small amounts of other minerals. It's a one-way reaction. No matter what kind of chemistry professor we use and no matter what process we use we can't turn these compounds back into a chemistry professor. Chemistry professors are unstable mixtures of predominantly unstable compounds which, in the exclusive presence of the sun's heat, decay irreversibly into simpler organic and inorganic compounds. That's a scientific fact. The question is: Then why does nature reverse this process? What on earth causes the inorganic compounds to go the other way? It isn't the sun's energy. We just saw what the sun's energy did. It has to be something else. What is it?"

"It has never been in my power to study anything, — mathematics, ethics, metaphysics, gravitation, thermodynamics, optics, chemistry, comparative anatomy, astronomy, psychology, phonetics, economics, the history of science, whist, men and women, wine, metrology, except as a study of semeiotic."

"The recognition of certain basic impossibilities has laid the foundations of some major principles of physics and chemistry; similarly, recognition of the impossibility of understanding living things in terms of physics and chemistry, far from setting limits to our understanding of life, will guide it in the right direction. And even if the demonstration of this impossibility should prove of no great advantage in the pursuit of discovery, such a demonstration would help to draw a truer image of life and man than that given us by the present basic concepts of biology."

"Be a physical chemist, an analytical chemist, an organic chemist, if you will; but above all, be a chemist"

"The ego becomes more like the inner ego and less like its old self, comparatively speaking. It accepts large portions of reality that it previously denied. Structurally, it remains intact, yet it has changed chemically and electromagnetically. Now it is far more open to inner data. Once this freedom is achieved, the ego can never return to its old state."

"I must confess it was very unexpected and I am very startled at my metamorphosis into a chemist."

"If some nuclear properties of the heavy elements had been a little different from what they turned out to be, it might have been impossible to build a bomb."

"Chemistry has been termed by the physicist as the messy part of physics, but that is no reason why the physicists should be permitted to make a mess of chemistry when they invade it."

"Professor Meitner stated that nuclear fission could be attributed to chemistry. I have to make a slight correction. Chemistry merely isolated the individual substances, but did not precisely identify them. It took Professor Hahn's method to do this. This was his achievement."

"I have described at some length the application of Positive Rays to chemical analysis; one of the main reasons for writing this book was the hope that it might induce others, and especially chemists, to try this method of analysis. I feel sure that there are many problems in chemistry, which could be solved with far greater ease by this than any other method. The method is surprisingly sensitive — more so than even that of spectrum analysis, requires an infinitesimal amount of material, and does not require this to be specially purified; the technique is not difficult if appliances for producing high vacua are available."

"I recognize nothing that is not material. In physics, chemistry and biology I see only mechanics. The Universe is nothing but an infinite and complex mechanism. Its complexity is so great that it borders on randomness, giving the illusion of free will."

"The philosophy of Bergson, which is a spiritualist restoration, essentially mystical, medieval, Quixotesque, has been called a demi-mondaine philosophy. Leave out the demi; call it mondaine, mundane. Mundane — yes, a philosophy for the world and not for philosophers, just as chemistry ought to be not for chemists alone. The world desires illusion (mundus vult decipi) — either the illusion antecedent to reason, which is poetry, or the illusion subsequent to reason, which is religion. And Machiavelli has said that whosoever wishes to delude will always find someone willing to be deluded. Blessed are they who are easily befooled!"

"Like literature, philosophy is not distinguished from other subjects by a specific approach to a subject-matter independent of it. Chemistry deals with chemicals, biology with life and astronomy with very large, very distant objects. Philosophy can boast no such definite subject-matter."

"The unique challenge which chemical synthesis provides for the creative imagination and the skilled hands ensures that it will endure as long as men write books, paint pictures, and fashion things which are beautiful, or practical, or both."

"Chemistry is the science of matter and the changes it can undergo. The world of chemistry therefore embraces everything material around us—the stones we stand on, the food we eat, the flesh we are made of, and the silicon we build into computers. There is nothing material beyond the reach of chemistry, be it living or dead, vegetable or mineral, on Earth or in a distant star."

"I was an atheist, finding no reason to postulate the existence of any truths outside of mathematics, physics and chemistry. But then I went to medical school, and encountered life and death issues at the bedsides of my patients. Challenged by one of those patients, who asked "What do you believe, doctor?", I began searching for answers."

"My first heresy says that all the fuss about global warming is grossly exaggerated. Here I am opposing the holy brotherhood of climate model experts and the crowd of deluded citizens who believe the numbers predicted by the computer models. Of course, they say, I have no degree in meteorology and I am therefore not qualified to speak. But I have studied the climate models and I know what they can do. The models solve the equations of fluid dynamics, and they do a very good job of describing the fluid motions of the atmosphere and the oceans. They do a very poor job of describing the clouds, the dust, the chemistry and the biology of fields and farms and forests. They do not begin to describe the real world that we live in. The real world is muddy and messy and full of things that we do not yet understand. It is much easier for a scientist to sit in an air-conditioned building and run computer models, than to put on winter clothes and measure what is really happening outside in the swamps and the clouds. That is why the climate model experts end up believing their own models."

"It's more interesting to work on challenges where you don’t know the answer. In chemistry, you should enter into an adventure with molecules"

"Mendeleev, unlike the squeamish Meyer, had balls enough to predict that new elements would be dug up. Look harder, you chemists and geologists, he seemed to taunt, and you’ll find them."

"You don't need something more to get something more. That's what emergence means. Life can emerge from physics and chemistry plus a lot of accidents. The human mind can arise from neurobiology and a lot of accidents, the way the chemical bond arises from physics and certain accidents. Doesn't diminish the importance of these subjects to know they follow from more fundamental things plus accidents."

"Chemistry is a game that electrons play."

"We are honored for research which is today referred to as the "Two Neutrino Experiment". How does one make this research comprehensible to ordinary people? In fact "The Two Neutrinos" sounds like an Italian dance team. How can we have our colleagues in chemistry, medicine, and especially in literature share with us, not the cleverness of our research, but the beauty of the intellectual edifice, of which our experiment is but one brick? This is a dilemma and an anguish for all scientists because the public understanding of science is no longer a luxury of cultural engagement, but it is an essential requirement for survival in our increasingly technological age: In this context, I believe this Nobel Ceremony with its awesome tradition and pomp has as one of its most important benefits; the public attention it draws to science and its practitioners."

"This new quantum mechanics promised to explain all of chemistry. And though I felt an exuberance at this, I felt a certain threat, too. “Chemistry,” wrote Crookes, “will be established upon an entirely new basis…. We shall be set free from the need for experiment, knowing a priori what the result of each and every experiment must be.” I was not sure I liked the sound of this. Did this mean that chemists of the future (if they existed) would never actually need to handle a chemical; might never see the colors of vanadium salts, never smell a hydrogen selenide, never admire the form of a crystal; might live in a colorless, scentless, mathematical world? This, for me, seemed and awful prospect, for I, at least, needed to smell and touch and feel, to place myself, my senses, in the middle of the perceptual world."

"All the elements other than hydrogen and helium make up just 0.04 percent of the universe. Seen from this perspective, the periodic system appears to be rather insignificant. But the fact remains that we live on the earth, which consists entirely of ordinary matter, as far as we know, and where the relative abundance of elements is quite different."

"Dead is when the chemists take over the subject."

"...when I started doing chemistry, I did it the way I fished – for the excitement, the discovery, the adventure, for going after the most elusive catch imaginable in uncharted seas."

"Chemists usually write about their chemical careers in terms of the different areas and the discrete projects in those areas on which they have worked. Essentially all my chemical investigations, however, are in only one area, and I tend to view my research not with respect to projects, but with respect to where I’ve been driven by two passions which I acquired in graduate school: I am passionate about the Periodic Table (and selenium, titanium and osmium are absolutely thrilling), and I am passionate about catalysis. What the ocean was to the child, the Periodic Table is to the chemist; new catalytic reactivity is, of course, my personal coelacanth."

"The most essential example of the theory of self-organisation in chemistry is the theory of non-linear, non-equilibrium thermodynamics of chemical reactions presented by Prigogine and his co-workers."

"Whether two molecules are (dis)similar is in the eye of the beholder. Scientists look to fool the receptor - but you really want to fool the patent office."

"Chemists have been inspired by Nature for hundreds of years, not only trying to understand the chemistry that occurs in living systems, but also trying to extend Nature based on the learned facts."

"Building art is a synthesis of life in materialised form. We should try to bring in under the same hat not a splintered way of thinking, but all in harmony together."

"Either one or the other [analysis or synthesis] may be direct or indirect. The direct procedure is when the point of departure is known-direct synthesis in the elements of geometry. By combining at random simple truths with each other, more complicated ones are deduced from them. This is the method of discovery, the special method of inventions, contrary to popular opinion."

"There is synthesis when, in combining therein judgments that are made known to us from simpler relations, one deduces judgments from them relative to more complicated relations. There is analysis when from a complicated truth one deduces more simple truths."

"The synthesis of pure, calming food is breathing pure air, listening to good sounds, looking at good sights, and touching pure objects."

"The world is not dialectical -- it is sworn to extremes, not to equilibrium, sworn to radical antagonism, not to reconciliation or synthesis. This is also the principle of evil."

"An example of such emergent phenomena is the origin of life from non-living chemical compounds in the oldest, lifeless oceans of the earth. Here, aided by the radiation energy received from the sun, countless chemical materials were synthesized and accumulated in such a way that they constituted, as it were, a primeval “soup.” In this primeval soup, by infinite variations of lifeless growth and decay of substances during some billions of years, the way of life was ultimately reached, with its metabolism characterized by selective assimilation and dissimulation as end stations of a sluiced and canalized flow of free chemical energy."

"The terms synthesis and analysis are used in mathematics in a more special sense than in logic. In ancient mathematics they had a different meaning from what they now have. The oldest definition of mathematical analysis as opposed to synthesis is that given in Euclid, XIII. 5, which in all probability was framed by Eudoxus: "Analysis is the obtaining of the thing sought by assuming it and so reasoning up to an admitted truth; synthesis is the obtaining of the thing sought by reasoning up to the inference and proof of it.""

"There is neither spirit nor matter in the world; the stuff of the universe is spirit-matter. No other substance but this could produce the human molecule. I know very well that this idea of spirit-matter is regarded as a hybrid monster, a verbal exorcism of a duality which remains unresolved in its terms. But I remain convinced that the objections made to it arise from the mere fact that few people can make up their minds to abandon an old point of view and take the risk of a new idea. … Biologists or philosophers cannot conceive a biosphere or noosphere because they are unwilling to abandon a certain narrow conception of individuality. Nevertheless, the step must be taken. For in fact, pure spirituality is as unconceivable as pure materiality. Just as, in a sense, there is no geometrical point, but as many structurally different points as there are methods of deriving them from different figures, so every spirit derives its reality and nature from a particular type of universal synthesis."

"Love is the affinity which links and draws together the elements of the world... Love, in fact, is the agent of universal synthesis."

"Life is not found in atoms or molecules or genes as such, but in organization; not in symbiosis but in synthesis."

"Mathematics as an expression of the human mind reflects the active will, the contemplative reason, and the desire for aesthetic perfection. Its basic elements are logic and intuition, analysis and construction, generality and individuality. Though different traditions may emphasize different aspects, it is only the interplay of these antithetic forces and the struggle for their synthesis that constitute the life, usefulness, and supreme value of mathematical science."

"The most dramatic moments in the development of physics are those in which great syntheses take place, where phenomena which previously had appeared to be different are suddenly discovered to be but different aspects of the same thing. The history of physics is the history of such syntheses, and the basis of the success of physical science is mainly that we are able to synthesize."

"Every truth has relation to some other. And we should try to write the facts of our knowledge so as to see them in their several bearings. This we do when we frame them into a system. To do so legitimately, we must begin by analysis and end with synthesis."

"Designer is defined as an emerging synthesis of artist, inventor, mechanic, objective economist and evolutionary strategist."

"I have no fault to find with those who teach geometry. That science is the only one which has not produced sects; it is founded on analysis and on synthesis and on the calculus; it does not occupy itself with the probable truth; moreover it has the same method in every country."

"Our movement took a grip on cowardly Marxism and from it extracted the meaning of socialism. It also took from the cowardly middle-class parties their nationalism. Throwing both into the cauldron of our way of life there emerged, as clear as a crystal, the synthesis -- German National Socialism. Nazism as cocktail of Marxism and bourgeois nationalism: a toxic brew indeed."

"Analysis and synthesis, though commonly treated as two different methods, are, if properly understood, only the two necessary parts of the same method. Each is the relative and correlative of the other. Analysis, without a subsequent synthesis, is incomplete ; it is a mean cut of from its end. Synthesis, without a previous analysis, is baseless ; for synthesis receives from analysis the elements which it recomposes."

"A man ... has two antagonists: the first presses him from behind, from the origin. The second blocks the road ahead. He gives battle to both. To be sure, the first supports him in his fight with the second, for he wants to push him forward, and in the same way the second supports him in his fight with the first, since he drives him back. But it is only theoretically so. For it is not only the two antagonists who are there, but he himself as well, and who really knows his intentions? His dream, though, is that some time in an unguarded moment and this would require a night darker than any night has ever been yet he will jump out of the fighting line and be promoted, on account of his experience in fighting, to the position of umpire over his antagonists in their fight with each other."

"To play chess on a truly high level requires a constant stream of exact, informed decisions, made in real time and under pressure from your opponent. What’s more, it requires a synthesis of some very different virtues, all of which are necessary to good decisions: calculation, creativity and a desire for results. If you ask a Grandmaster, an artist and a computer scientist what makes a good chess player, you’ll get a glimpse of these different strengths in action."

"Man is a synthesis of psyche and body, but he is also a synthesis of the temporal and the eternal. In the former, the two factors are psyche and body, and spirit is the third, yet in such a way that one can speak of a synthesis only when the spirit is posited. The latter synthesis has only two factors, the temporal and the eternal. Where is the third factor? And if there is no third factor, there really is no synthesis, for a synthesis that is a contradiction cannot be completed as a synthesis without a third factor, because the fact that the synthesis is a contradiction asserts that it is not. What, then, is the temporal?"

"Science is spectral analysis. Art is light synthesis."

"There are many reasons for carrying out the laboratory synthesis of an organic compound. In the pharmaceutical industry, new molecules are designed and synthesized in the hope that some might be useful new drugs. In the chemical industry, syntheses are done to devise more economical routes to known compounds. In academic laboratories, the synthesis of extremely complex molecules is sometimes done just for the intellectual challenge involved in mastering so difficult a subject. The successful synthesis route is a highly creative work that is sometimes described by such subjective terms as elegant or beautiful."

"The artist does not illustrate science; … [but] he frequently responds to the same interests that a scientist does, and expresses by a visual synthesis what the scientist converts into analytical formulae or experimental demonstrations."

"By this way of Analysis we may proceed from Compounds to Ingredients, and from Motions to the Forces producing them; and in general, from Effects to their Causes, and from particular Causes to more general ones, till the Argument end in the most general. This is the Method of Analysis: and the Synthesis consists in assuming the Causes discover'd, and establish'd as Principles, and by them explaining the Phænomena proceeding from them, and proving the Explanations."

"The world is a very strange place, and there are times when the metaphorical or narrative description characteristic of culture and the material representation so integral to science appear to touch, when everything comes together—when life and art reflect each other equally."

"Enhance and intensify one's vision of that synthesis of truth and beauty which is the highest and deepest reality."

"Chemical synthesis is one of the key technologies that form the basis of modern drug discovery and development. For the rapid preparation of new test compounds and the development of candidates with often highly complex chemical structures, it is essential to use state-of-theart chemical synthesis technologies."

"Poetry is the synthesis of hyacinths and biscuits."

"We are approaching a new age of synthesis. Knowledge cannot be merely a degree or a skill... it demands a broader vision, capabilities in critical thinking and logical deduction without which we cannot have constructive progress."

"Analysis and synthesis ordinarily clarify matters for us about as much as taking a Swiss watch apart and dumping its wheels, springs, hands, threads, pivots, screws and gears into a layman's hands for reassembling, clarifies a watch to a layman."

"Synthetic method is that which begins with the parts, and leads onward to the knowledge of the whole : it begins with the most simple principles and general truths, and proceeds by degrees to that which is drawn from them, or compounded of them ; and therefore it is called the method of composition."

"Get the habit of analysis- analysis will in time enable synthesis to become your habit of mind."

"The overall yield in a multistep step synthesis is the product of the yields for each separate step. In a linear synthetic scheme, the hypothetical TM is assembled in a stepwise manner. … Since the overall yield of the TM decreases as the number of individual steps increases, a convergent synthesis should be considered in which two or more fragments of the TM are prepared separately and then joined at the latest-possible stage of the synthesis. It should be noted, however, that the simple overall yield calculation is some- what misleading since it is computed on one starting material, whereas several are used and the number of reactions is the same! Nevertheless, the increased efficiency of a convergent synthesis compared to the linear approach is derived from the fact that the preparation of a certain amount of a product can be carried out on a smaller scale."

"The world has arisen in some way or another. How it originated is the great question, and Darwin's theory, like all other attempts to explain the origin of life, is thus far merely conjectural. I believe he has not even made the best conjecture possible in the present state of our knowledge."

"An example of such emergent phenomena is the origin of life from non-living chemical compounds in the oldest, lifeless oceans of the earth. Here, aided by the radiation energy received from the sun, countless chemical materials were synthesized and accumulated in such a way that they constituted, as it were, a primeval “soup.” In this primeval soup, by infinite variations of lifeless growth and decay of substances during some billions of years, the way of life was ultimately reached, with its metabolism characterized by selective assimilation and dissimulation as end stations of a sluiced and canalized flow of free chemical energy."

"It is mere rubbish thinking, at present, of origin of life; one might as well think of origin of matter. —"

"The fine-tuning of the universe, about which cosmologists make such a to-do, is both complex and specified and readily yields design. So too, Michael Behe's irreducibly complex biochemical systems readily yield design. The complexity-specification criterion demonstrates that design pervades cosmology and biology. Moreover, it is a transcendent design, not reducible to the physical world. Indeed, no intelligent agent who is strictly physical could have presided over the origin of the universe or the origin of life."

"It is as though a puzzle could be put together simply by shaking its pieces."

"Life could spread from planet to planet or from stellar system to stellar system, carried on meteors."

"Believing the first cell originated by chance is like believing a tornado ripping through a junkyard full of airplane parts could produce a Boeing 747."

"You know, my brothers, the nature of our business. The child you see before you, thanks to a talisman stolen from the powers of Earth, is able to take possession of the Blue Bird and thus to snatch from us the secret which we have kept since the origin of life... Now we know enough of Man to entertain no doubt as to the fate which he reserves for us once he is in possession of this secret. That is why it seems to me that any hesitation would be both foolish and criminal... It is a serious moment; the child must be done away with before it is too late..."

"Q: Strange, isn't it, Jean-Luc? Everything you know... your entire civilization... it all begins right here in this little pond of goo. It's appropriate somehow, isn't it? Too bad you didn't bring a microscope -- this is quite fascinating. Here they go... the amino acids are moving closer... closer...closer...Ohhhh! Nothing happened! You see what you've done?"

"Although each individual resonance form seems to imply that benzene has alternating single and double bonds, neither form is correct by itself. The true benzene structure is a hybrid of the two individual forms, and all six carbon–carbon bonds are equivalent. This symmetrical distribution of electrons around the molecule is evident in an electrostatic potential map."

"When first dealing with resonance forms, it’s useful to have a set of guidelines that describe how to draw and interpret them. The following rules should be helpful: … Individual resonance forms are imaginary, not real. … Resonance forms differ only in the placement of their π or nonbonding electrons. … Different resonance forms of a substance don’t have to be equivalent. … Resonance forms obey normal rules of valency. … The resonance hybrid is more stable than any individual resonance form."

"A substance showing resonance between two or more valence-bond structures does not contain molecules with the configurations and properties usually associated with these structures."

"Does the carbonate ion have one uncharged oxygen atom bound to carbon through a double bond and two other oxygen atoms bound through a single bond each, both bearing a negative charge, as suggested by the Lewis structures? Or, to put it differently, are A, B, and C equilibrating isomers? The answer is no... It is said to be delocalized, in accord with the tendency of electrons to “spread out in space”. In other words, none of the individual Lewis representations of this molecule is correct on its own. Rather, the true structure is a composite of A, B, and C. The resulting picture is called a resonance hybrid."

"Some molecules cannot be described accurately by one Lewis structure but exist as hybrids of several resonance forms. To find the most important resonance contributor, consider the octet rule, make sure that there is a minimum of charge separation, and place on the relatively more electronegative atoms as much negative and as little positive charge as possible."

"The carbohydrates are naturally organic compounds containing carbon,hydrogen and oxygen.Their ratio of hydrogen to oxygen in water is 2:1,the no.of simpler carbohydrate molecules obtained upon hydrolysis determines the class of a particular carbon hydrate."

"MOLECULE, n. The ultimate, indivisible unit of matter. It is distinguished from the corpuscle, also the ultimate, indivisible unit of matter, by a closer resemblance to the atom, also the ultimate, indivisible unit of matter. Three great scientific theories of the structure of the universe are the molecular, the corpuscular and the atomic. A fourth affirms, with Haeckel, the condensation of precipitation of matter from ether -- whose existence is proved by the condensation of precipitation. The present trend of scientific thought is toward the theory of ions. The ion differs from the molecule, the corpuscle and the atom in that it is an ion. A fifth theory is held by idiots, but it is doubtful if they know any more about the matter than the others."

"Deep in the sea all molecules repeat the patterns of one another till complex new ones are formed. They make others like themselves and a new dance starts.Growing in size and complexity living things masses of atoms DNA, protein dancing a pattern ever more intricate."

"Such a shared-electron bond, first proposed in 1916 by G. N. Lewis, is called a covalent bond. The neutral collection of atoms held together by covalent bonds is called a molecule."

"A diatomic molecule is a molecule with one atom too many."

"A simple way of indicating the covalent bonds in molecules is to use what are called Lewis structures, or electron-dot structures, in which the valence shell electrons of an atom are represented as dots. … Simpler still is the use of Kekulé structures, or line-bond structures, in which a two-electron covalent bond is indicated as a line drawn between atoms."

"Valence electrons that are not used for bonding are called lone-pair electrons, or nonbonding electrons. … As a time-saving shorthand, nonbonding electrons are often omitted when drawing line-bond structures, but you still have to keep them in mind since they’re often crucial in chemical reactions."

"Organic molecules are usually drawn using either condensed structures or skeletal structures. In condensed structures, carbon–carbon and carbon–hydrogen bonds aren’t shown. In skeletal structures, only the bonds and not the atoms are shown. A carbon atom is assumed to be at the ends and at the junctions of lines (bonds), and the correct number of hydrogens is mentally supplied."

"Net molecular polarity is measured by a quantity called the dipole moment and can be thought of in the following way: assume that there is a center of mass of all positive charges (nuclei) in a molecule and a center of mass of all negative charges (electrons). If these two centers don’t coincide, then the molecule has a net polarity. The dipole moment, μ (Greek mu), is defined as the magnitude of the charge Q at either end of the molecular dipole times the distance r between the charges, μ = Q × r. Dipole moments are expressed in debyes(D), where 1 D = 3.336 ×10-30 coulomb meter (C · m) in SI units. For example, the unit charge on an electron is 1.60 ×10-19 C. Thus, if one positive charge and one negative charge are separated by 100 pm (a bit less than the length of a typical covalent bond), the dipole moment is 1.60 ×10-29 C · m, or 4.80 D.… In contrast with water, methanol, and ammonia, molecules such as carbon dioxide, methane, ethane, and benzene have zero dipole moments. Because of the symmetrical structures of these molecules, the individual bond polarities and lone-pair contributions exactly cancel."

"In my own field, x-ray crystallography, we used to work out the structure of minerals by various dodges which we never bothered to write down, we just used them. Then Linus Pauling came along to the laboratory, saw what we were doing and wrote out what we now call Pauling's Rules. We had all been using Pauling's Rules for about three or four years before Pauling told us what the rules were."

"...all the work of the crystallographers serves only to demonstrate that there is only variety everywhere they suppose uniformity...that innature there is nothing absolute, nothing perfectly regular."

"I miss the old days, when nearly every problem in X-ray crystallography was a puzzle that could be solved only by much thinking."

"Since modern crystallography dawned with X-ray diffraction experiments on crystals by Max von Laue in 1912 and William and Lawrence Bragg (a father and son team) in 1913, and was recognized by Nobel prizes in physics for von Laue in 1914 and the Braggs in 1915, the discipline has informed almost every branch of the natural sciences."

"Aeroplanes fly safely because crystallography tests computer models of materials under stress. Drugs are more potent because crystallographers can see and modify how molecules interact with target sites in cells. An X-ray diffraction instrument on NASA’s Curiosity rover is now even studying the mineralogy of Mars."

"Crystallography is increasingly focusing its resources on large multidisciplinary facilities, such as powerful X-ray and neutron sources."

"Crystallographers have a raft of methods at their disposal. Von Laue scattered X-ray photons from atoms. Now experimenters can also bombard crystal lattices with electrons and neutrons, and exploit properties such as the polarization of photons and neutrons and their interactions with magnetic fields."

"It takes a very special breed of scientist to do this work...it is an area of science in which women dominate."

"Thanks to the methods that [Crystallographers] have devised for investigating crystal structures, an entirely new world has been opened and has already in part been explored with marvelous exactitude. The significance of these methods, and of the results attained by their means, cannot as yet be gauged in its entirety, however imposing its dimensions already appear to be."

"Crystallography remains a cutting-edge field, and one that, if harnessed properly, could contribute as much in the next 100 years as it did in the previous 100. The development of the x-ray free-electron laser, for example, is a monumental technical achievement, and one that seems more suited to the world of 2114 than 1914, or even 2014."

"Crystallographers should take a lesson from particle physicists and create a body run by scientists for the governance of large international x-ray and neutron facilities. It should be guided by input from regular meetings of researchers from across the scientific community. This will ensure that the next generation of infrastructure will have the strongest possible scientific case, articulated clearly."

"Researchers hope to be able to get diffraction patterns from individual molecules, allowing them to watch biomolecules moving and interacting in a completely natural setting, surrounded by water, instead of trapped in the artificial environment of a crystal. That’s my future vision for crystallography. Get away from being a coroner imaging dead molecules, and instead get molecular movies."

"In general, the rate of evaporation (m) of a substance in a high vacuum is related to the pressure (p) of the saturated vapor by the equation m=\sqrt{\frac{M}{2\pi RT}}p. Red phosphorus and some other substances probably form exceptions to this rule."

"In 1763 a Croatian Jesuit named Roger Joseph Boscovich (1711 - 1787) identified the ultimate implication of this mechanical atomic theory. One of the crucial aspects of Isaac Newton's laws of motion is their predictive capability. If we know how an object is moving at any instant - how fast, and in which direction - and if, furthermore, we know the forces acting on it, we can calculate its future trajectory exactly. This predictability made it possible for astronomers to use Newton's laws of motion and gravity to calculate, for example, when future solar eclipses would happen. Boscovich realized that if all the world is just atoms in motion and collision, then an all-seeing mind "could, from a continuous arc described in an interval of time, no matter how small, by all points of matter, derive the law [that is, a universal map] of forces itself … Now, if the law of forces were known, and the position, velocity and direction of all the points at any given instant, it would be possible for a mind of this type to foresee all the necessary subsequent motions and states, and to predict all the phenomena that necessarily followed from them.""

"We have come a long way from the classical ideal of objective descriptions. In quantum mechanics the departure from this ideal has been even more radical. We can still use the objectifying language of classical physics to make statements about observable facts. For instance, we can say that a photographic plate has been blackened, or that cloud droplets have formed. But we can say nothing about the atoms themselves."

"Who sees the future? Let us have free scope for all directions of research; away with dogmatism, either atomistic or anti-atomistic!"

"It seems not absurd to conceive that at the first Production of mixt Bodies, the Universal Matter whereof they among other Parts of the Universe consisted, was actually divided into little Particles of several sizes and shapes variously mov'd."

"Neither is it impossible that of these minute Particles divers of the smallest and neighbouring ones were here and there associated into minute Masses or Clusters, and did by their Coalitions constitute great store of such little primary Concretions or Masses as were not easily dissipable into such Particles as compos'd them."

"I shall not peremptorily deny, that from most of such mixt Bodies as partake either of Animal or Vegetable Nature, there may by the Help of the Fire, be actually obtain'd a determinate number (whether Three, Four or Five, or fewer or more) of Substances, worthy of differing Denominations."

"It may likewise be granted, that those distinct Substances, which Concretes generally either afford or are made up of, may without very much Inconvenience be call'd the Elements or Principles of them."

"And, to prevent mistakes, I must advertize You, that I now mean by Elements, as those Chymists that speak plainest do by their Principles, certain Primitive and Simple, or perfectly unmingled bodies; which not being made of any other bodies, or of one another, are the Ingredients of which all those call'd perfectly mixt Bodies are immediately compounded, and into which they are ultimately resolved: now whether there be any one such body to be constantly met with in all, and each, of those that are said to be Elemented bodies, is the thing I now question."

"Fraunhofer's publication of 1814 did not receive prompt recognition, nor did his papers of 1821 and 1823. Physicists were fighting over the emission and wave theories of light. The attention of chemists was concentrated upon Dalton's atomic theory and the Berthollet-Proust controversy over the law of definite proportions. The full explanation of the new fact brought forth by Fraunhofer was not given for nearly forty years. He himself had failed to find the key to the hieroglyphics of the solar lines, the "Fraunhofer lines," nor had he clearly defined the role which the spectral lines were destined to play in chemical analysis."

"To try to make a model of an atom by studying its spectrum is like trying to make a model of a grand piano by listening to the noise it makes when thrown downstairs."

"In 1738 Daniel Bernoulli correctly derived Boyle's law by assuming gases consisted of collections of particles that continuously collided with the container walls."

"Dalton did not propose atoms as an abstraction or mathematical device; Dalton's atoms were physical. ...Despite its foundation in dubious hypothesis and its erroneous initial results, Dalton's theory was just the breakthrough that was needed. For the first time it allowed chemists to interpret mass relationships rationally."

"I have raised a question which may be regarded as heretical. At the time when our modern conception of chemistry first dawned... the average chemist... accepted the elements as ultimate facts... absolutely simple, incapable of transmutation or decomposition, each a kind of barrier behind which we could not penetrate. ...[H]e said they were self-existent from all eternity ...But in our times... we cannot help asking what are the elements, whence do they come, what is their signification? ...These elements perplex us in our researches, baffle us in our speculations, and haunt us in our very dreams. They stretch like an unknown sea before us—mocking, mystifying and murmuring strange revelations and possibilities. If I venture to say that... elements are not simple and primordial... but have evolved from simpler matters—or... one sole kind of matter—I... give formal utterance to an idea... for some time "in the air" of science. Chemists, physicists, philosophers of the highest merit declare explicitly their belief that the seventy... elements of our text-books are not the which we must never hope to pass."

"Sweet exists by convention, bitter by convention, colour by convention; atoms and Void (alone) exist in reality."

"By convention (νόμω) sweet is sweet, by convention bitter is bitter, by convention hot is hot, by convention cold is cold, by convention color is color. But in reality there are atoms and the void. That is, the objects of sense are supposed to be real and it is customary to regard them as such, but in truth they are not. Only the atoms and the void are real"

"There cannot exist any atoms or parts of matter that are of their own nature indivisible. For however small we suppose these parts to be, yet because they are necessarily extended, we are always able in thought to divide any one of them into two or more smaller parts, and may accordingly admit their divisibility. ...and although we should even suppose that God had reduced any particle of matter to a smallness so extreme that it did not admit of being further divided, it would nevertheless be improperly styled indivisible, for though God had rendered the particle so small that it was not in the power of any creature to divide it, he could not however deprive himself of the ability to do so... Wherefore, absolutely speaking, the smallest extended particle is always divisible..."

"If the idea of physical reality had ceased to be purely atomic, it still remained for the time being purely mechanistic; people still tried to explain all events as the motion of inert masses; indeed no other way of looking at things seemed conceivable. Then came the great change, which will be associated for all time with the names of Faraday, Clerk Maxwell, and Hertz."

"If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis... that all things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied."

"The atomic theory was not generally accepted in the time of Democritus, largely because of its deterministic character, for it allows no chance, choice, or free will."

"The problem was that although ideas like statistical mechanics and the kinetic theory worked at the practical level to provide a mathematical description of what was going on, nobody had seen atoms—more to the point, given the technology of the time it was physically impossible to see atoms. This left the door open to for philosophers such as Ernst Mach to argue that the atomic hypothesis was no more than a hypothesis, what is known as a heuristic device, meaning just because things in the macroscopic world behave as if they were made of atoms that doesn't prove that they are... Mach regarded atoms as no more than a convenient fiction, which provided a basis for physicists to make calculations; anything that could not be detected by the human senses, he argued, was not the proper subject of scientific debate. Einstein disagreed, and argued the case for atoms with his friends. He became obsessed with the idea, and determined that if no one else could prove that atoms were real, he would do it himself."

"In the Brownian motion paper, Einstein... calculations involved the relationship between osmotic pressure, viscosity, and the way individual particles suspended in the liquid diffuse... He realized that the kick produced by a single molecule hitting a particle as large as a pollen grain could not produce a measurable shift... But the large particle is constantly being bombarded... if you take a very small time interval, then just by chance at that instant the particle will be receiving more kicks on one side. The combined effect will shift the particle by a minute amount... Einstein discovered that it gradually moved farther from its starting point... as a random walk. He showed the distance ... depends on the square root of the time... This is called "root mean square" displacement and the equation Einstein worked out for displacement involves the temperature of the liquid, its viscosity, the radius of the particle and Avogadro's number. ...He also realized that if the predicted displacement could be measured... the same equation... could be used to give a value of Avogadro's number. ...It was extremely difficult to make the observations... but in 1908... Jean-Baptiste Perrin finally succeeded. ...Perrin's results exactly matched the predictions from Einstein's theory. ...The whole package finally established the reality of atoms and molecules, and the validity of the kinetic theory..."

"Light and matter are both single entities, and the apparent duality arises in the limitations of our language. It is not surprising that our language should be incapable of describing the processes occurring within the atoms, for, as has been remarked, it was invented to describe the experiences of daily life, and these consist only of processes involving exceedingly large numbers of atoms. Furthermore, it is very difficult to modify our language so that it will be able to describe these atomic processes, for words can only describe things of which we can form mental pictures, and this ability, too, is a result of daily experience. Fortunately, mathematics is not subject to this limitation, and it has been possible to invent a mathematical scheme — the quantum theory — which seems entirely adequate for the treatment of atomic processes; for visualisation, however, we must content ourselves with two incomplete analogies — the wave picture and the corpuscular picture."

"The thought of the great epistemological difficulties with which the visual atom concept of earlier physics had to contend gives us the hope that the abstracter atomic physics developing at present will one day fit more harmoniously into the great edifice of Science."

"There is a fundamental error in separating the parts from the whole, the mistake of atomizing what should not be atomized. Unity and complementarity constitute reality."

"It was the quantitative relationship between electrochemical change and current which interested Faraday... It was not until after Faraday's death that the significance of his laws of electrolysis for atomic theory was realized. In 1881 von Helmholtz pointed out that if elementary substances are composed of atoms, it follows from Faraday's laws of electrolysis that electricity also is composed of elementary portions which behave like atoms of electricity. Investigations on the conduction of electricity by gases led to the identification of the electron as the fundamental unit of electricity at the end of the century. Faraday's positive and negative ions are therefore atoms (or groups of atoms or radicals) with a deficiency or an excess of an integral number of electrons, where the integral number is the valency of the atom. The ions move in opposite directions through the solution to the electrodes where their charges are neutralised, causing them to be discharged to neutral atoms or radicals. These are the primary electrode reactions, of which the deposition of silver on a platinum cathode in the silver coulometer is a typical example."

"I adopt Mr. Darwin's hypothesis, therefore, subject to the production of proof that physiological species may be produced by selective breeding; just as a physical philosopher may accept the undulatory theory of light, subject to the proof of the existence of the hypothetical ether; or as the chemist adopts the atomic theory, subject to the proof of the existence of atoms; and for exactly the same reasons, namely, that it has an immense amount of primâ facie probability: that it is the only means at present within reach of reducing the chaos of observed facts to order; and lastly, that it is the most powerful instrument of investigation which has been presented to naturalists since the invention of the natural system of classification and the commencement of the systematic study of embryology."

"With respect to the ultimate constitution of... masses, the same two antagonistic opinions which had existed since the time of Democritus and of Aristotle were still face to face. According to the one, matter was discontinuous and consisted of minute indivisible particles or atoms, separated by a universal vacuum; according to the other, it was continuous, and the finest distinguishable, or imaginable, particles were scattered through the attenuated general substance of the plenum. A rough analogy to the latter case would be afforded by granules of ice diffused through water; to the former, such granules diffused through absolutely empty space."

"In the latter part of the eighteenth century, the chemists had arrived at several very important generalisations... However plainly ponderable matter seemed to be originated and destroyed in their operations, they proved that, as mass or body, it remained indestructible and ingenerable... a certain number of the chemically separable kinds of matter were unalterable by any known means (except in so far as they might be made to change their state from solid to fluid, or vice versâ)... and that the properties of these several kinds of matter were always the same, whatever their origin. All other bodies were found to consist of two or more of these, which thus took the place of the four 'elements' of the ancient philosophers. Further, it was proved that, in forming chemical compounds, bodies always unite in a definite proportion by weight, or in simple multiples of that proportion, and that, if any one body were taken as a standard, every other could have a number assigned to it as its proportional combining weight. It was on this foundation of fact that Dalton based his re-establishment of the old atomic hypothesis on a new empirical foundation."

"The gradual reception of the undulatory theory of light necessitated the assumption of the existence of an 'ether' filling all space. But whether this ether was to be regarded as a strictly material and continuous substance was an undecided point, and hence the revived atomism escaped strangling in its birth. For it is clear, that if the ether is admitted to be a continuous material substance, Democritic atomism is at an end and Cartesian continuity takes its place."

"The real value of the new atomic hypothesis... did not lie in the two points which Democritus and his followers would have considered essential—namely, the indivisibility of the 'atoms' and the presence of an interatomic vacuum—but in the assumption that, to the extent to which our means of analysis take us, material bodies consist of definite minute masses, each of which, so far as physical and chemical processes of division go, may be regarded as a unit—having a practically permanent individuality. ...that smallest material particle which under any given circumstances acts as a whole."

"At times the success of a concept in one area of science may have a retarding effect upon progress in other areas. ..."the Law of Definite Proportions," was established... only after a long battle between Berthollet and Proust. The success of the Proust position was so decisive that the matter received little critical study during the decades which followed. Possibly this was for the best as far as the progress of chemistry was concerned. Had chemists concerned themselves with the composition of solutions, glasses, and alloys the establishment of atomic theory might have been even slower than it was."

"Anyone who had studied the vicissitudes of atomic theory during the period between 1810 and 1860 recognizes the tremendous problems which faced chemists of that day in connection with atomic weights, equivalent weights, reliable formulas, and matters of that sort. The Law of Definite Proportions was a useful concept in helping bring order out of chaos. ...Had chemists had to face the fact of variable composition in some of their common compounds it is doubtful if atomic theory might have been established as soon as it was. It is in solid state chemistry that the Law of Definite Proportions has been found wanting. Not only in the case of metallic compounds are peculiar atomic ratios of the component elements to be found, but even in such solids as metallic oxides and sulfides. Ferrous oxide (FeO) presents a particularly fine example... Although the compound is frequently mentioned in freshman chemistry courses to illustrate the Law of Definite Proportions... on accurate analysis... the ratio is somewhat between the range of 0.84 to 0.95 atoms of iron per atom of oxygen. ...The existence of a considerable number of such compounds has led to the proposal that compounds be classified as Berthollides and Daltonides; the term Berthollide referring to such compounds as cuprous sulfide with a somewhat variable domposition, and Daltonide referring to those with precisely fixed atomic ratios."

"It is sometimes desirable to have experimental data which is not completely precise. Had Berthollet been successful in convincing the chemical world that compounds do not have fixed proportions, the development of the atomic theory would have been greatly hindered. The fact that the Proust position became the accepted one in view of the work of Dalton, meant that the trials and errors toward a successful formulation of chemical compounds would ultimately succeed on the basis of an atomic philosophy. Once the atomic philosophy was clearly developed, the existence of the Berthollides could still be incorporated into chemical philosophy on the basis of studies of solid state physics. This illustrates clearly... the fact that science progresses from one state of approximation to another, and that progress may well be hindered when so much precise information is available that broad and useful concepts are overlooked."

"Now his principal doctrines were these. That atoms and the vacuum were the beginning of the universe; and that everything else existed only in opinion."

"His opinions are these. The first principles of the universe are atoms and empty space; everything else is merely thought to exist. The worlds are unlimited; they come into being and perish. Nothing can come into being from that which is not nor pass away into that which is not. Further, the atoms are unlimited in size and number, and they are borne along in the whole universe in a vortex, and therby generate all composite things – fire, water, air, earth; for even these are conglomerations of given atoms. And it is because of their solidity that these atoms are impassive and unalterable. The sun and the moon have been composed of such smooth and spherical masses [i.e. atoms], and so also the soul, which is identical with reason. We see by virtue of the impact of images upon our eyes."

"All those who maintain a vacuum are more influenced by imagination than by reason. When I was a young man, I also gave in to the notion of a vacuum and atoms; but reason brought me into the right way. ...The least corpuscle is actually subdivided in infinitum, and contains a world of other creatures, which would be wanting in the universe, if that corpuscle was an atom, that is, a body of one entire piece without subdivision. In like manner, to admit a vacuum in nature, is ascribing to God a very imperfect work... space is only an order of things as time also is, and not at all an absolute being. ...Now, let us fancy a space wholly empty. God could have placed some matter in it, without derogating in any respect from all other things: therefore he hath actually placed some matter in that space: therefore, there is no space wholly empty: therefore all is full. The same argument proves that there is no corpuscle, but what is subdivided. ...there must be no vacuum at all; for the perfection of matter is to that of a vacuum, as something to nothing. And the case is the same with atoms: What reason can any one assign for confining nature in the progression of subdivision? These are fictions merely arbitrary, and unworthy of true philosophy. The reasons alleged for a vacuum, are mere sophisms."

"Loschmidt reasoned that in a liquid, the atoms or molecules would be more or less squeezed up against each other, so the volume of a liquid would be straightforwardly the volume of an individual molecule multiplied by the number of them. ...The diameter he came up with was a little less than one millionth of a millimeter—by modern standards a pretty fair answer. ...To critics... Loschschmidt's analysis still didn't prove anything. ...in the absence of tangible evidence that atoms existed, it was mere mathematics, empty theorizing. Loschmidt had shown that if atoms existed, they must have a certain size—but that first "if" had not been overcome."

"Traditionally, [physics] had concerned itself with searching out quantitative relationships between measurable phenomena... To go beyond this, to explain observable facts in terms of unobservable but alledgedly "real" entities such as atoms, was to go beyond what many physicists regarded as the limits of their discipline. What was happening in the second half of the 19th century, was the birth of the subject we now call theoretical physics... a puzzling innovation. ...As well as having a hand in kinetic theory, ...In 1864, ...Maxwell's theory introduced a new idea, the electromagnetic field. Over atoms and electromagnetic fields, the same question arose: real or imaginary?"

"The last thirty years have seen the beginning and development of a new period in physics and chemistry, namely the atomic period. In contrast to the period preceding it where nature's processes were described in terms of continua, recent developments have emphasized the discrete structure of the submicroscopic universe. Thus, today one hears of the atoms of matter, the atoms of electricity, and even the atoms of energy, the quanta. ...[T]he atomic theory of matter is the oldest and perhaps the most complete. ...[B]ecause of its relative simplicity the problem of the atomic theory of gases, in the form of the kinetic theory of gases, has attained the highest degree of perfection in this field. Its admirable methods of analysis are therefore indispensable..."

"Heraclitus. ...change and incessant movement is the basis, and the only basis, of all things and that what is illusory is the idea of a central, or indeed of any other, unity: the Universe is a stream of incessant and infinitely minute changes. The Atomists. From this springs naturally the atomistic theory of Leucippus and Democritus. This theory is an endeavour to give a sort of solidity and reality to the mutability of Heraclitus, whilst retaining his controversial advantages in the denial of an all-embracing One. The veritable original of things is taken by these Atomists to be, not one, but innumerable, indefinitely minute, homogeneous atoms, the mere mechanical combination of which makes up the variety of nature."

"However well fitted atomic theories may be to reproduce certain groups of facts, the physical inquirer who has laid to heart Newton's rules will only admit those theories as provisional helps. and will strive to attain, in some more natural way, a satisfactory substitute."

"The atomic theory plays a part in physics similar to that of certain auxilliary concepts in mathematics; it is a mathematical model for facilitating the mental reproduction of facts. Although we represent vibrations by the harmonic formula, the phenomena of cooling by exponentials, falls by squares of times, etc., no one will fancy that vibrations in themselves have anything to do with the circular functions, or the motions of falling bodies with squares. It has simply been observed that the relations between the quantities investigated were similar to certain relations obtaining between familiar mathematical functions, and these more familiar ideas are employed as an easy means of supplementing experience. Natural phenomena whose relations are not similar to those functions with which we are familiar, are at present very difficult to reconstruct. But the progress of mathematics may facilitate the matter."

"Avogadro... suggested in 1811 that the same volumes of different gases contain the same number of particles under the same conditions of temperature and pressure. ...Avogadro's hypothesis raised the difficulty that when one volume of hydrogen combined with one volume of chlorine, two volumes of hydrogen chloride were produced, implying that the atoms of hydrogen and chlorine were split into halves during the process of combination. Avogadro overcame this difficulty by supposing that the fundamental particles of hydrogen, chlorine, and other gases, were molecules containing two atoms of the element, and that chemical combination between two gases resulted in the splitting up of the elementary molecules and the formation of compound molecules in which there was one atom of each element... Avogadro's hypothesis... was not accepted until the 1860's, as it demanded that the atoms of the same element should combine together to form molecules. Dalton and others rejected such a conception, for they held that like atoms must repel one another and could not combine. Moreover, Dalton... thought that the various species of atoms differed not only in their atomic weights, but also in their sizes, and the number per unit volume in the gaseous state."

"In studying the constitution of bodies we are forced from the very beginning to deal with particles which we cannot observe. For whatever may be our ultimate conclusions as to molecules and atoms, we have experimental proof that bodies may be divided into parts so small that we cannot perceive them. Hence, if we are careful to remember that the word particle means a small part of a body, and that it does not involve any hypothesis as to the ultimate divisibility of matter, we may consider a body as made up of particles, and we may also assert that in bodies or parts of bodies of measurable dimensions, the number of particles is very great indeed."

"The ancient Greek philosopher, Democritus, propounded an hypothesis of the constitution of matter, and gave the name of atoms to the ultimate unalterable parts of which he imagined all bodies to be constructed. In the 17th century, Gassendi revived this hypothesis, and attempted to develope it, while Newton used it with marked success in his reasonings on physical phenomena; but the first who formed a body of doctrine which would embrace all known facts in the constitution of matter, was Roger Joseph Boscovich, of Italy, who published at Vienna, in 1759, a most important and ingenious work, styled Theoria Philosophiæ Naturalis ad unicam legem virium, in Natura existentium redacta. This is one of the most profound contributions ever made to science; filled with curious and important information, and is well worthy of the attentive perusal of the modern student. In more recent days, the theory of Boscovich has received further confirmation and extension in the researches of Dalton, Joule, Thomson, Faraday, Tyndall, and others."

"The atomic theory may be regarded in two distinct ways, ...The older and vague atomic theory professed to be a theory of the constitution of bodies and to afford the basis for a physical explanation of physical phenomena; in order to do this, forces of attraction and repulsion between the particles of matter had to be assumed, and elaborate calculations as to the integral or resultant effect of these elementary forces had to be instituted, or at least formulated. ...ingenious as those theories were, they led to no results in the direction of the calculation of the molar and molecular properties of bodies, or if they did, they yielded none which could not be gained by the opposite view which regarded matter as continuous. The atomic theory, however, did good service from another point of view, when through Richter, Dalton, Proust, and Berzelius the fact that bodies combine only in definite proportions of weight, or their simple multiples, became firmly established. The authors of this discovery were driven to the atomic view of matter as the most convenient method of expressing the formulæ of chemical compounds."

"There is here a whole new branch of spectroscopy, which is sure to tell one much about the nature of an atom."

"In... A New System of Chemical Philosophy published in 1808, John Dalton laid the foundations of the atomic theory: he assumed chemical action to be an action between very minute particles of elements and compounds, and all the minute particles of the same element, or compound, to be exactly the same size and weight. ...his hypothesis assumed the accuracy and universal applicability of those generalisations which are now called the laws of chemical combination."

"Now, if the molecules possess anything which is ever so distantly related to sensation, and we cannot doubt it, since each one feels the presence, the certain condition, the peculiar forces of the other, and, accordingly, has the inclination to move, and under circumstances really begins to move—becomes alive as it were; moreover, since such molecules are the elements which cause pleasure and pain; if, therefore, the molecules feel something that is related to sensation, then this must be pleasure, if they can respond to attraction and repulsion, i.e. follow their inclination or disinclination; it must be displeasure if they are forced to execute some opposite movement, and it must be neither pleasure nor displeasure if they remain at rest."

"If a fluid be composed of particles mutually flying [fleeing from] each other, and the density be as the compression, the centrifugal forces [repulsion] of the particles will be reciprocally proportional to the distances of their centres. And, vice versa, particles flying each other with forces that are reciprocally proportional to the distances of their centres, compose an elastic [liquid or gas], whose density is as the compression."

"Dalton, the mathematical tutor, following up the lead of Newton, combined the whole of the results of quantitative measurement which had accumulated up to his time, in a comprehensive theory, based on the concept of the chemical atom."

"The results of a scrutiny of the materials of chemical science from a mathematical standpoint are pronounced in two directions. In the first we observe crude, qualitative notions, such as fire-stuff, or phlogiston, destroyed; and at the same time we perceive definite measurable quantities such as fixed air, or oxygen, taking their place. In the second direction we notice the establishment of generalizations, laws, or theories, in which a mass of quantitative data is reduced to order and made intelligible. Such are the law of conservation of matter, the laws of chemical combination, and the atomic theory."

"The Atomic Theory and the Periodic Law have been given prominence, since their neglect unfailingly leads to obscurity and triviality."

"The old mechanical and atomic hypotheses have, during recent years, become so plausible that they have ceased to seem like hypotheses; atoms are no longer just a convenient fiction. It seems almost as if we could see them, now that we know how to count them. ...The kinetic theory of gases has thus received unexpected corroboration. ...The remarkable counting of the number of atoms by Perrin completed the triumph of the atomic theory. ...In the processes used with the Brownian phenomenon, or in those used for the law of radiation, we do not deal directly with the number of atoms, but with their degrees of freedom of movement. In that process where we consider the blue of the sky, the mechanical properties of the atoms come into play; the atoms are looked upon as producing an optical discontinuity. ...The atom of the chemist is now a reality. But that does not mean that we have reached the ultimate limit of the divisibility of matter. When Democritus invented the atom he considered it as the absolutely indivisible element within which there would be nothing further to distinguish. That is what the word meant in Greek. ... the atom of the chemist would not have satisfied him since that is not indivisible; it is not a true element; it is not free from mystery, from secrets. The chemist's atom is a universe. Democritus would have considered, even after so much trouble in finding it, that we were still only at the beginning of our search—these philosophers are never satisfied. ...This atom disintegrates into yet smaller atoms. What we call radioactivity is the perpetual breaking up of atoms. ...Each atom is like a sort of solar system where the small negative electrons play the role of planets revolving around the great... sun. ...the atom of a radioactive body is a universe within itself and a world subject to chance."

"The study of the radio-active substances and of the discharge of electricity through gases has supplied very strong experimental evidence in support of the fundamental ideas of the existing atomic theory. It has also indicated that the atom itself is not the smallest unit of matter but is a complicated structure made up of a number of smaller bodies."

"What we are nowadays hearing of the language of spectra is a true 'music of the spheres' in order and harmony that becomes ever more perfect in spite of the manifold variety. The theory of spectral lines will bear the name of Bohr for all time. But yet another name will be permanently associated with it, that of Planck. All integral laws of spectral lines and of atomic theory spring originally from the quantum theory. It is the mysterious organon on which Nature plays her music of the spectra, and according to the rhythm of which she regulates the structure of the atoms and nuclei."

"The atomistic theory of matter appears in well established and elaborated form in various systems of Hindu philosophy... The oldest of these systems... appears to be that of the Vaiseshika, attributed to Kanada... Whether or no the... theory antedated Democritus... is... uncertain. Professor Garbe's opinion is that beyond a doubt the Indian theory is a long time after the theory of Leucippus and Democritus. L. Mabilleau, on the other hand, considers the Vaiseshika system as several centuries earlier than Democritus. ...This theory recognizes nine distinct entities constituting the universe. These are earth, water, fire, air (or wind), ether (akasa), time, space, soul, and "manas." ...Time, space, and soul are not material, though existent. The "manas" is the medium through which impressions of sense are conveyed to the soul. The first four, therefore, correspond to the four elements of Empedocles; the fifth, ether, can be compared with little similarity to the ether of Aristotle. The first four elements are composed of atoms which are eternal, never created nor destroyed. Each of these four elements exists as atoms and also as aggregates of atoms. As atoms, they are imperishable. The elements which we see or feel are aggregates of atoms and as such are subject to change, but the atoms, which are invisible, do not change. ...Akasa, or ether, is assumed not to consist of atoms, but is infinite in extent, continuous and eternal. It cannot be apprehended by the senses, but is the carrier of sound. It is also described... as all-pervasive, occupying the same space that is occupied by the various forms of matter, and therefore devoid of the property of impenetrability, characterizing the atoms of other elements."

"Boyle entertains the hypothesis of a universal matter, the concept of atoms of different shapes and sizes, and the possibility of existence of substances that might properly be called elements... The atomic theory as originally conceived by Democritus and Epicurus, developed by Lucretius, and resurrected by Gassendi from about 1647 on, was doubtless the source from which Boyle derived his ideas, ...as he cites both Epicurus and Gassendi. Boyle, however... avoids any dogmatic assertion of these hypotheses. It is plain, however, that these atoms or "corpuscles" as he calls them are a constant element of his thought."

"The final step... came in the late 1850s. Up to that time [evidence supporting] the atomic theory had been entirely... chemical... Within... physics, however, the theory had made little progress beyond the brilliant guesswork of Newton's Optics. As a result of Clausius' and Maxwell's new theory of heat and gases, physics at last caught up with chemistry. ...This theory was not entirely new. In outline its mathematical foundations had been worked out [as early as the 1730s] by Daniel Bernoulli... [who] demonstrated that random agitation of the atoms of air would explain Boyle's Law just as well as Newton's theory of repulsive forces; but although ... extended this explanation into a dynamical theory of heat it remained a minority view... overshadowed by Boerhaave's and Lavoisier's [heat as a] material theory. Around 1800... a few... were positively sceptical about caloric... Benjamin Thompson... observed that friction would generate unlimited quantities of heat... though... the material theory retained the allegiance of leading scientists for another half-century."

"Between Bernoulli and Maxwell... Euler, d'Alembert, Lagrange and Hamilton expounded Newton's dynamics] in more and more general forms, until at last all [mechanical] processes... were seen as conforming to... the Principle of the Conservation of Energy, and the Principle of Least Action. This mathematical drive... continued, overflowing beyond... mechanics... [and into] processes involving nonmechanical factors: heat, electricity, vitality, and chemical change... The most comprehensive exposition was given in 1847 by Hermann von Helmholtz... In 1848, J. P. Joule [demonstrated that]... whether he produced heat by the passage of an electric current, or by mechanical effort, the conversion took place at fixed, measurable rates. ...[I]t was natural to look again for an explanation ...Perhaps the production of heat by friction merely transferred mechanical energy from a visible level to an invisible one... the increased motion of the molecules... Clausius and Maxwell turned this view... into a fully-developed branch of mathematics (...from 1857 to 1866.) ...[H]eat theory had been united into the general theory of 'matter in motion'... the random agitation of vast numbers of invisibly-small particles."

"From Dalton in 1803 to Maxwell in 1866 the atomic picture of matter had progressively taken on shape and detail: by Maxwell's time it... lay at the heart of the classical system. ...all matter was composed of ponderable atoms and, with the 'death' of caloric, the division between corporeals and incorporeals became absolutely sharp. The known incorporeal agencies—radiant heat, light, magnetisim and electricity—had to be dealt with in terms of other concepts."

"The question whether our elementary atoms are in their nature indivisible, or whether they are built up of smaller particles, is one upon which I, as a chemist, have no hold whatever, and I may say that in chemistry the question is not raised by any evidence whatever."

"The physical doctrine of the atom has got into a state which is strongly suggestive of the epicycles of astronomy before Copernicus."

"The absence of effects due to the earth's motion relative to the ether can be explained on the electromagnetic theory if it is supposed that this theory covers all phenomena. This appears to be a strong argument in favor of the purely electrical nature of matter. It will be convenient now to mention the chief electrical theories of atomic structure which have been proposed. According to Sir J. J. Thomson, atoms consist of solid spheres of positive electricity inside which negative electrons move about freely. ...The electrons will distribute themselves uniformly throughout the sphere so as to neutralize it as completely as possible and can vibrate about their positions of equilibrium. According to Sir J. Larmor, atoms consist of a number of positive and negative electrons describing orbits about each other. ...On this view an atom is a sort of small gaseous nebula without any sort of solid foundation. A third theory recently adopted by Rutherford regards the atom as containing a nucleus of positive electricity with negative electrons outside it; probably describing orbits around it. On this view the atom is a sort of minute solar system. The positive nucleus... provides a definite foundation fixing the identity of the atom. The same may be said of the sphere in Sir J. J. Thomson's theory. ... The most important property of atoms is their extraordinary stability... Negative electrons can be knocked out of atoms by the impact of rapidly moving particles such as the cathode rays and α rays, yet the atoms retain their identity and after regaining negative electrons are unaffected. Facts like these appear to be decisive against Sir J. Larmor's theory. ... These [monatomic] gases ...give spectra containing many lines so that it is certain that their atoms contain electrons which can vibrate. It is necessary to suppose that collisions between these atoms do not set their electrons in vibration, which seems to require the electrons to be protected in some way. This seems to be strongly in favor of Sir J. J. Thomson's theory and against the other two theories, for if the electrons were describing orbits outside it is hard to see how they could escape violent disturbance during a collision. ... Sir J. Larmor's theory and Rutherford's planetary theory are difficult to reconcile with the idea that atoms become firmly fixed together in compounds and rigid solids. On such theories we should expect to have nothing but gases and liquids and only very simple compounds. ... The scattering of α rays led Rutherford to adopt the idea of a positive nucleus, since some α rays are turned through a larger angle than can be explained by the electric forces due to a charge equal to that on one electron. It may be, however, that other forces besides ordinary electric force act on α rays when moving through matter. The α rays are helium atoms which have a radius about 10-8 cm., so that they probably only get through by displacing the atoms of the matter. If we suppose the positive sphere of one atom can not penetrate into that of another then the scattering of a rays by matter can probably be explained on Sir J. J. Thomson's theory."

"Have not the small Particles of Bodies certain Powers, Virtues, or Forces, by which they act at a distance, not only upon the Rays of Light for reflecting, refracting, and inflecting them, but also upon one another for producing a great Part of the Phænomena of Nature? For it's well known that Bodies act one upon another by the Attractions of Gravity, Magnetism, and Electricity; and these Instances shew the Tenor and Course of Nature, and make it not improbable but that there may be more attractive Powers than these. For Nature is very consonant and conformable to her self. How these Attractions may be perform'd, I do not here consider. What I call Attraction may be perform'd by impulse, or by some other means unknown to me. I use that Word here to signify only in general any Force by which Bodies tend towards one another, whatsoever be the Cause. For we must learn from the Phenomena of Nature what Bodies attract one another, and what are the Laws and Properties of the Attraction, before we enquire the Cause by which the Attraction is perform'd. The Attractions of Gravity, Magnetism, and Electricity, reach to very sensible distances, and so have been observed by vulgar Eyes, and there may be others which reach to so small distances as hitherto escape Observation; and perhaps electrical Attraction may reach to such small distances, even without being excited by Friction."

"And when Water and Oil of Vitriol poured successively into the same Vessel grow very hot in the mixing, does not this Heat argue a great Motion in the Parts of the Liquors? And does not this Motion argue, that the Parts of the two Liquors in mixing coalesce with Violence, and by consequence rush towards one another with an accelerated Motion?"

"And when Aqua fortis, or Spirit of Vitriol poured upon Filings of Iron, dissolves the Filings with a great Heat and Ebullition, is not this Heat and Ebullition effected by a violent Motion of the Parts, and does not that Motion argue that the acid Parts of the Liquor rush towards the Parts of the Metal with violence, and run forcibly into its Pores till they get between its outmost Particles, and the main Mass of the Metal, and surrounding those Particles loosen them from the main Mass, and set them at liberty to float off into the Water? And when the acid particles, which alone would distil with an easy Heat, will not separate from the Particles of the Metal without a very violent Heat, does not this confirm the Attraction between them?"

"And is it not from the mutual Attraction of the Ingredients that they stick together for compounding these Minerals... And the same Question may be put concerning all, or almost all the gross Bodies in Nature. For all the Parts of Animals and Vegetables are composed of Substances volatile and fix'd, fluid and solid, as appears by their Analysis; and so are Salts and Minerals, so far as Chymists have been hitherto able to examine their Composition."

"The Parts of all homogeneal hard Bodies which fully touch one another, stick together very strongly. And for explaining how this may be, some have invented hooked Atoms, which is begging the Question; and others tell us that Bodies are glued together by rest, that is, by an occult Quality, or rather by nothing; and others, that they stick together by conspiring Motions, that is, by relative rest amongst themselves. I had rather infer from their Cohesion, that their Particles attract one another by some Force, which in immediate Contact is exceeding strong, at small distances performs the chymical Operations above-mention'd, and reaches not far from the Particles with any sensible Effect."

"If two plane polish'd Plates of Glass... be laid together, so that their sides be parallel and at a very small distance from one another, and then their lower edges be dipped into Water, the Water will rise up between them. And the less the distance of the Glasses is, the greater will be the height to which the Water will rise. ...And in like manner, Water ascends between two Marbles polish'd plane, when their polished sides are parallel, and at a very little distance from one another. And if slender Pipes of Glass be dipped at one end into stagnating Water, the Water will rife up within the Pipe, and the height to which it rises will be reciprocally proportional to the Diameter of the Cavity of the Pipe, and will equal the height to which it rises between two Planes of Glass, if the Semidiameter of the Cavity of the Pipe be equal to the distance between the Planes, or thereabouts. And these Experiments succeed after the same manner in vacuo as in the open Air, (as hath been tried before the Royal Society,) and therefore are not influenced by the Weight or Pressure of the Atmosphere. ...There are therefore Agents in Nature able to make the Particles of Bodies stick together by very strong Attractions. And it is the Business of experimental Philosophy to find them out."

"And thus Nature will be very conformable to her self and very simple, performing all the great Motions of the heavenly Bodies by the Attraction of Gravity which intercedes those Bodies, and almost all the small ones of their Particles by some other attractive and repelling Powers which intercede the Particles. The Vis inertiæ is a passive Principle by which Bodies persist in their Motion or Rest, receive Motion in proportion to the Force impressing it, and resist as much as they are resisted. By this principle alone there never could have been any Motion in the World. Some other Principle was necessary for putting Bodies into Motion; and now they are in Motion, some other Principle is necessary for conserving the Motion."

"Analytical chemistry is extremely important—probably even more important than analytical chemists think. Everything in science requires measurement; analytical chemists are experts in the science of measurement, not just in determining the structures of molecules and the compositions of mixtures of molecules."

"The wave equation was quickly followed by remarkably similar equations for gravitation, electrostatics, elasticity, and heat flow. Many bore the names of their inventors: Laplace's equation, Poisson's equation. The equation for heat does not; it bears the unimaginative and not entirely accurate name 'heat equation'. It was introduced by Joseph Fourier, and his ideas led to the creation of a new area of mathematics whose ramifications were to spread far beyond its original source."

"Plastic pollution free world is not a choice but a commitment to life - a commitment to the next generation."

"Waste-water from the houses collected in the gutters running alongside the curbs and emitted a truly fearsome smell. There were no public toilets in the streets or squares. Visitors, especially women, often became desperate when nature called. In the public buildings the sanitary facilities were unbelievably primitive....As a metropolis, Berlin did not emerge from a state of barbarism into civilization until after 1870."

"Worldwide, pharmaceutical use has been on the increase for the past century and will continue to increase into the future with the development of new medicines to cure recently discovered diseases as well as previously untreatable conditions. Following use by the patient, active pharmaceutical ingredients (APIs) and their metabolites are excreted to the sewerage system. They are then typically transported to a wastewater treatment works, where, depending on their molecular structure and physicochemical properties, they can be either degraded by biological treatment processes or released to the environment in effluents or sorb to sludge. The soil environment will therefore be exposed to APIs and their metabolites when sludge from treatment processes is applied to land as an agricultural fertilizer or when soil is irrigated with reclaimed wastewater effluent. While only a few studies have explored the occurrence of APIs in the soil environment, available data indicate that a range of API classes, including nonsteroidal anti-inflammatory drugs, antidepressants, anticonvulsants, and antibacterial agents do occur in soils in concentrations up to the low mg/kg level. Because of detection of pharmaceuticals in soils, concerns have been raised over the potential for these substances to be taken up into human food items and to pose a risk to human health. A number of studies have demonstrated the uptake of pharmaceuticals used in human and veterinary medicine into plants. Studies have explored the uptake and translocation of a variety of APIs with a particular focus on the antidepressant drug fluoxetine and antibacterial chemicals including sulfamethazine, sulfamethoxazole, and trimethoprim into numerous plant species including root and shoot crops such as soybean, lettuce, and carrot."

"By examining conditions in China and experimenting in a lab, the scientists suggest that a combination of weather patterns and chemistry could have caused London fog to turn into a haze of concentrated sulfuric acid."

"Mr. President, I find it encouraging that you are proposing an initiative for reducing air pollution. Accepting the urgency, it seems clear to me also that climate change is a problem which can no longer be left to a future generation."

"Pollution is nothing but resources we're not harvesting. We allow them to disperse because we've been ignorant of their value. But if we got onto a planning planning basis, the government could trap pollutants in the stacks and spillages and get back more money than this would cost out of the stockpiled chemistries they'd be collecting."

"Plastic pollution in the form of small particles (diameter less than 5 mm)—termed "microplastic"—has been observed in many parts of the world ocean. They are known to interact with biota on the individual level, e.g. through ingestion, but their population-level impacts are largely unknown. One potential mechanism for microplastic-induced alteration of pelagic ecosystems is through the introduction of hard-substrate habitat to ecosystems where it is naturally rare. Here, we show that microplastic concentrations in the North Pacific Subtropical Gyre (NPSG) have increased by two orders of magnitude in the past four decades, and that this increase has released the pelagic insect Halobates sericeus from substrate limitation for oviposition. High concentrations of microplastic in the NPSG resulted in a positive correlation between H. sericeus and microplastic, and an overall increase in H. sericeus egg densities. Predation on H. sericeus eggs and recent hatchlings may facilitate the transfer of energy between pelagic- and substrate-associated assemblages. The dynamics of hard-substrate-associated organisms may be important to understanding the ecological impacts of oceanic microplastic pollution."

"The fact that both human sperm count and insect biomass are estimated to be declining at about 2 percent per year may be just a numerical coincidence. Nevertheless, it’s a number that should grab our attention. [...] Unless the chemical load on the environment is radically reduced, and soon, the stakes may be existential. If sexually reproducing animals, including humans, lose the ability to yield offspring, then in the future the biosphere may host a radically reduced roster of higher life forms. Meanwhile, the public should be warned more explicitly and urgently about the perils of chemical exposure, and provided with information about the products most likely implicated. With regard to climate change one often hears the refrain, “We don’t need to ‘save the planet’; the Earth will be fine, it’s just humans that will suffer.” In reality, some environmental trends now in motion, including the widespread release of endocrine-disrupting chemicals, are imperiling all of nature. Are rubber duckies and other plastic crap, overly manicured lawns, throw-away packaging material, and cheap cookware really worth that level of risk?"

"Continued unrestricted testing by the nuclear powers, joined in time by other nations which may be less adept in limiting pollution, will increasingly contaminate the air that all of us must breathe. Even then, the number of children and grandchildren with cancer in their bones, with leukemia in their blood, or with poison in their lungs might seem statistically small to some, in comparison with natural health hazards. But this is not a natural health hazard -- and it is not a statistical issue. The loss of even one human life, or the malformation of even one baby -- who may be born long after we are gone -- should be of concern to us all. Our children and grandchildren are not merely statistics toward which we can be indifferent."

"Wildfires, heat domes, hurricanes, and extreme weather events are hard to ignore; yet, much to the consternation of environmental activists, a significant segment of the population continues to deny anthropogenic global warming. Even among environmental advocates, there is often a tendency to view the rise in diseases such as cancer, Parkinson’s disease, and heart, liver, and kidney diseases—along with neurological disorders—as merely bad luck or the result of poor genetics. The difficulty in definitively linking these disorders to the increasing presence of chemical toxins and microplastics allows agrochemical, petrochemical, and pharmaceutical companies to continue their practices without accountability. The industrial use of glyphosate and other pesticides, PFAS, heavy metals, dioxins, phthalates, and VOCs continues to accumulate in our environment, creating an ever more toxic planet. Bioaccumulation may be the most dangerous term that people either don’t understand or don’t know. Every person and organism has physiological thresholds for warding off viruses, bacteria, and chemical toxins, which, when exceeded, can lead to illness, disease, or even death. Much to the delight of chemical companies, the greatest threats to our biosphere—chemical toxins and waste—often go unnoticed."

"The lower spheres are so polluted that one could say without exaggeration that meteoric dust is being oxidized because of the chemical reactions of psychic energy, which first of all act upon metals… Of course, the pollution of the spheres closest to our planet is disastrous. The lower subtle bodies loiter about like swindlers at a bazaar and thereby prevent the successful formation of a spiral of constructive effort. One has to harbor a special aspiration in order to penetrate beyond the bounds of these dreadful deposits. So we should not believe that there might be thoughts without consequences; even the largest cup can be overfilled! This especially applies to rotation, when gravity holds back many particles of lighter weight. So when We speak about the vital need to purify psychic energy through refinement of thought, We have in mind the purification of the lower spheres. To borrow the language of the Church, it is necessary to conquer the infernal hordes."

"If we some day choke on the pollution of our own air, there will be little consolation in leaving behind a dying continent ringed with steel."

"In 1991, Landsat captured the devastating environmental consequences of war. As Iraqi forces withdrew from Kuwait, they set fire to over 650 oil wells and damaged almost 75 more, which then spewed crude oil across the desert and into the Persian Gulf. Fires burned for ten months. According to a 2009 study published in Disaster Prevention and Management, firefighting crews from ten countries, part of a response team that comprised approximately 11,450 workers from 38 countries, used familiar and also never-before-tested technologies to put out the fires. When the last one was extinguished in November, about 300 lakes of oil remained, as well as a layer of soot and oil that fell out of the sky and mixed with sand and gravel to form 'tarcrete' across 5 percent of Kuwait's landscape. An estimated one to 1.5 billion barrels of oil were released into the environment. After most burned, 25 to 40 million barrels ended up spread across the desert and 11 million barrels in the Persian Gulf, according to a 2012 paper published in Remote Sensing of Environment. For comparison, the 2010 Deepwater Horizon spill into the Gulf of Mexico is estimated to have released nearly 5 million barrels of oil. Kuwait's landscape has recovered somewhat. Clean up efforts have removed 21 million barrels of oil from the desert, but an estimated 1 million barrels still remain."

"“There really have been no studies that have associated the [pharmaceutical] residues in our water with human health problems,” says Ilene Ruhoy, a pediatric neurologist and environmental toxicologist who has studied the issue. That could be a sign that they pose no threat, but like Wilson, Ruhoy stresses how difficult it is to do these types of studies. “You’re talking about exposure to parts per million, parts per billion. And it’s a combination of drugs. It’s not just one drug in the water, it’s multitudes of. It’s exposure to these very, very minute amounts of these drugs, but many drugs over decades—ten, 20, 30, 40, 50, 60 years.”"

"Net-based surveys are less subjective than direct observations but are limited regarding the area that can be sampled (net apertures 1–2 m and ships typically have to slow down to deploy nets, requiring dedicated ship's time). The plastic debris sampled is determined by net mesh size, with similar mesh sizes required to make meaningful comparisons among studies. Floating debris typically is sampled with a neuston or manta trawl net lined with 0.33 mm mesh. Given the very high level of spatial clumping in marine litter, large numbers of net tows are required to adequately characterize the average abundance of litter at sea. Long-term changes in plastic meso-litter have been reported using surface net tows: in the North Pacific Subtropical Gyre in 1999, plastic abundance was 335 000 items/km2 and 5.1 kg/km2, roughly an order of magnitude greater than samples collected in the 1980s. Similar dramatic increases in plastic debris have been reported off Japan. However, caution is needed in interpreting such findings, because of the problems of extreme spatial heterogeneity, and the need to compare samples from equivalent water masses, which is to say that, if an examination of the same parcel of water a week apart is conducted, an order of magnitude change in plastic concentration could be observed."

"“There’s been a fair amount of work done in both the U.S. and Canada as well as Europe that documents [pharmaceuticals] in wastewater and in water,” says Joanna Wilson, a biologist at McMaster University in Ontario, Canada. She studies how drugs in the water affect zebrafish, a tiny freshwater fish in the minnow family. More recent data shows that the same types of compounds are in drinking water. One study found several pharmaceuticals in treated tap water, including atenolol (a beta-blocker), carbamazepine (an anticonvulsant), gemfibrozil (an antilipidemic), meprobamate (an antianxiety medication), and phenytoin (an anticonvulsant). The concentrations of these compounds were very low, usually less than 10 nanograms per liter, which is parts per trillion. For reference, one part per trillion is equivalent to about one second in 64 years. “We have an aging demographic, and we have an increased reliance, in North America and Europe in particular, with the treatment of health concerns with pharmaceuticals.” This translates to more medicines making their way into the water system, and we need to determine how to deal with it, she says. “Long-term exposures [to pharmaceuticals] are quite a bit different than short term exposures, and we need to really start testing and figuring out if chronic exposures of low doses are relevant for the health of an individual or population of animals.”"

"Now Mayow, like Boyle, conceived the air as made up of minute particles, while he restricted himself to two varieties, those, namely, which are necessary to life, called by him "spiritus igno-aereus," and those incapable of supporting respiration or combustion, which are left after the removal of this "spiritus." Since a mixture of saltpetre and sulphur continued burning even under water, he assumed that his igno-aereal particles must also be contained in the salt. Acids too contained the new principle. ...Mayow died in 1679 at the age of thirty-four years; had he lived but a little longer, it can scarcely be doubted that he would have forestalled the revolutionary work of Lavoisier, and stifled the theory of phlogiston at its birth. As it was, his work, though rendered in one of the most luminous and convincing scientific publications of the period, was immediately forgotten, and so proved of little effect on the evolution of our modern chemical system."

"If I were giving this lecture fifty years from now, the word "gravitation" would be as old-fashioned as the word "phlogiston" is to us. Relativity has certainly demoted gravitation as a real explanation, just as Priestley's and Lavoisier's analyses and decoding of chemical reactions destroyed the word "phlogiston.""

"From inflammable air and dephlogisticated air water is produced."

"One of the most fundamental principles of Lavoisier's chemistry was the use of numbers, notably in relation to what we often call today the principle of ... The principle implies that the experimenter must not only keep account of all the reacting solids and liquids, but also the gases—that is, all of the products. ...This rule led to quantitative experiments. Lavoisier was not the first person to use numbers in chemistry but he was a pioneer in using such numerical measurements as the basis of his system of chemistry. ...When Lavoisier first announced this law, chemists generally believed in... "phlogiston" which supposedly entered into chemical reactions (such as combustion) but had no weight. It was a radical step, therefore, for Lavoisier to base a system of chemistry on a balance of weights and to maintain that chemistry is not concerned with weightless "substances." ...this was indeed a chemical revolution."

"Intelligent design... is not a scientific argument at all, but a religious one. It might be worth discussing in a class on the history of ideas, in a philosophy class on popular logical fallacies, or in a comparative religion class on origin myths from around the world. But it no more belongs in a biology class than alchemy belongs in a chemistry class, phlogiston in a physics class or the stork theory in a sex education class. In those cases, the demand for equal time for "both theories" would be ludicrous. Similarly, in a class on 20th-century European history, who would demand equal time for the theory that the Holocaust never happened?"

"My thesis, paradoxically, and a little provocatively, but nonetheless genuinely, is simply this:PROBABILITY DOES NOT EXIST.The abandonment of superstitious beliefs about the existence of Phlogiston, the Cosmic Ether, Absolute Space and Time, ... , or Fairies and Witches, was an essential step along the road to scientific thinking. Probability, too, if regarded as something endowed with some kind of objective existence, is no less a misleading misconception, an illusory attempt to exteriorize or materialize our true probabilistic beliefs."

"Some hold that fundamental ideas have changed so often within science—especially within physics—that we should always expect our current views to turn out to be wrong. Sometimes this argument is called the “pessimistic meta-induction.” The prefix “meta” is misleading here, because the argument is not an induction about inductions; it’s more like an induction about explanatory inferences. So let’s call it "the pessimistic induction from the history of science." The pessimists give long lists of previously posited theoretical entities like phlogiston and caloric that we now think do not exist... Optimists reply with long lists of theoretical entities that once were questionable but which we now think definitely do exist—like atoms, germs, and genes."

"Lacan goes wrong by relying (quite uncritically!) on Saussure's signifier-signified conception of language. It is understandable that Lacan, when he began to write in the 1930s, should learn Saussure's turn-of-the-century linguistics. But even at the end of his life he and now his followers write about signifiers and signifieds as though the Chomskyan revolution in linguistics had never happened. Contemporary literary theorists tirelessly quote Saussure. But why? Today's linguists no more use Saussure's model than today's physicists use the concept of phlogiston. ...My point is not that Chomsky is right but that Saussure and Lacan are wrong."

"When Priestley described his discovery... he introduced... an open admission of the role of randomness in his work—even including a subtle dig at the theoretical, synthetic mode of Newton and his followers:More is owing to what we call chance... to the observation of events arising from unknown causes, than to any proper design, or preconceived theory in this business. ......But ...Priestley himself was trapped in a preconceived theory ...almost entirely unfounded, though he clung to it for the rest of his life. ...Priestley seared it directly into the name he gave his pure air: dephlogisticated air. That awkward name came from the closest thing to a dominant research paradigm in... : the phlogiston theory, one of the all-time classics in the history of human error."

"The same point can be made at least equally effectively in reverse: there is no such thing as research without counterinstances. For what is it that differentiates normal science from science in a crisis state? Not, surely, that the former confronts no counterinstances. On the contrary, what we previously called the puzzles that constitute normal science exist only because no paradigm that provides a basis for scientific research ever completely resolves all its problems. The very few that have ever seemed to do so (e.g., geometric optics) have shortly ceased to yield research problems at all and have instead become tools for engineering. Excepting those that are exclusively instrumental, every problem that normal science sees as a puzzle can be seen, from another viewpoint, as a counterinstance and thus as a source of crisis. Copernicus saw as counterinstances what most of Ptolemy’s other successors had seen as puzzles in the match between observation and theory. Lavoisier saw as a counterinstance what Priestley had seen as a successfully solved puzzle in the articulation of the phlogiston theory. And Einstein saw as counterinstances what Lorentz, Fitzgerald, and others had seen as puzzles in the articulation of Newton’s and Maxwell’s theories. Furthermore, even the existence of crisis does not by itself transform a puzzle into a counterinstance. There is no such sharp dividing line. Instead, by proliferating versions of the paradigm, crisis loosens the rules of normal puzzle-solving in ways that ultimately permit a new paradigm to emerge. There are, I think, only two alternatives: either no scientific theory ever confronts a counterinstance, or all such theories confront counterinstances at all times."

"All ['s] calculation is founded on the supposition that the calcination of metals is the result of the loss of phlogiston. But what I have been saying (...well known by now) is that this loss of phlogiston, even in the presence of metals is, according to me, nothing but pure supposition. What is more real, what can be known, by the balance and direct measurements, is that in all metallic s, whether made in the dry or humid way, whether... with the aid of air or water, or by means of acids, there is an augmentation of weight of the metal... due to the addition of vital air, or specifically the oxygen principle."

"Finding air necessary for the of fire, Scheele first turned his attention to its analysis; he found that solution of liver of sulphur, and certain other sulphureous compounds, occasioned a diminution in the bulk of air, to which they were exposed, equal to one part in about five, the flame of hydrogen and that sulphur caused a similar decrease of bulk in air standing over water, and lime-water not being rendered in either case turbid by the residuums, no fixed air was formed. He then obtains empyreal air (oxygen) by the decomposition , and other processes; describes the method of transferring, collecting, and examining the gases, and endeavours to prove that heat is a compound of empyreal air and phlogiston; he also shows by direct experiments, that the absorption occasioned in atmospheric air by liver of sulphur, is referrible to the abstraction of its empyreal portion; that it totally absorbs empyreal air, and that, upon adding to the residuary portion of atmospheric air, a quantity of empyreal air, equal to that absorbed by the sulphureous liquor, an air is again compounded, similar in all respects to that of the atmosphere. The identity of these investigations with those of Priestley will not fail of being observed, but... although Priestley was in the field a little before him, Scheele was unacquainted with his proceedings."

"The state of the science at present more nearly resembles the condition of a hundred years ago than the majority of chemists imagine. The latest development of organic chemistry, especially since the great activity in the dye and colour industries, resembles the last stage of the phlogistic period, when new compounds of great importance were being continually discovered, but the quantitative relations between the bodies used in their preparation were considered only as they influenced the yield of the product sought. As Lavoisier introduced weight and measure into the chemistry of the phlogistians, so will the new doctrine of the action of mass determine the direction of the science in the future."

"In 1774, Scheele obtained a yellow gas by digesting marine acid with manganese (manganese dioxide). As Scheele supposed that the manganese withdrew phlogiston from the acid, he called the new gas dephlogisticated marine acid. When, at a later time, phlogiston was regarded by some chemists as identical with , Scheele's view of the relation between the compositions of marine acid and the gas he obtained by the reaction of that acid with manganese oxide was interpreted to mean that the gas was produced by removing hydrogen from the acid. In accordance with his conception of the composition of acids, Lavoisier regarded muriatic acid to be a compound of oxygen; and in order to trace a likeness between the supposed composition of this acid and the compositions of other acids, he asserted that muriatic acid is formed by the union of oxygen with a hypothetical substance which he named radical muriatique. Lavoisier described the reaction between muriatic acid and manganese oxide as an oxidation of the acid; he said that the addition of a second dose of oxygen made the acid more volatile, but less acidic. He named Scheele's yellow gas acide muriatique oxygéné."

"The extension of Black's method by the physicist Lavoisier led to the downfall of the purely qualitative theory of phlogiston, and gave to chemistry the true methods of investigation, and its first great quantitative law—the law of ."

"The results of a scrutiny of the materials of chemical science from a mathematical standpoint are pronounced in two directions. In the first we observe crude, qualitative notions, such as fire-stuff, or phlogiston, destroyed; and at the same time we perceive definite measurable quantities such as fixed air, or oxygen, taking their place. In the second direction we notice the establishment of generalizations, laws, or theories, in which a mass of quantitative data is reduced to order and made intelligible. Such are the law of , the laws of chemical combination, and the atomic theory."

"In the course of my inquiries I was... soon satisfied that atmospherical air is not an unalterable thing; for that, according to my first hypothesis, the phlogiston with which it becomes loaded from bodies burning in it, and animals breathing it, and various other chemical processes, so far alters and depraves it, as to render it altogether unfit for inflammation, respiration, and other purposes to which it is subservient; and I had discovered that agitation in water, the process of vegetation, and probably other natural processes, restore it to its original purity."

"In aesthetic discourse, no interpretative-critical analysis, doctrine or programme is superseded, is erased, by any later construction. The Copernican theory did correct and supersede that of Ptolemy. The chemistry of Lavoisier makes untenable the early phlogiston theory. Aristotle on mimesis and pathos is not superseded by Lessing or Bergson. The Surrealist manifestos of Breton do not cancel out Pope's Essay on Criticism though they may well be antithetical to it."

"[M]etals remained the alchemists' chief concern... they seemed in their own way alive, whereas the calces (s) from which they were manufactured crumbled to dust and looked like cinders. Theory at once suggested a natural analogy. The metal was formed from the calx by the incorporation of or spirit; and this theory of metal-formation long remained in favour, being revived around 1700 as the 'phlogiston' theory. The central problem about metals was to identify the volitile constituents which combined with the calces to form the finished metal. For a long time, the status of quicksilver was ambiguous... resembling much more the volitile reagents which corrode metallic surfaces: mercury, in fact, forms an amalgam with other metals, and is even capable of dissolving gold... So the Alchemy of Avicenna classed mercury as a 'spirit' rather than a 'body'..."

"This statement appears to us to be conclusive with respect to the insufficiency of the undulatory theory, in its present state, for explaining all the phenomena of light. But we are not therefore by any means persuaded of the perfect sufficiency of the projectile system: and all the satisfaction that we have derived from an attentive consideration of the accumulated evidence, which has been brought forward, within the last ten years, on both sides of the question, is that of being convinced that much more evidence is still wanting before it can be positively decided. In the progress of scientific investigation, we must frequently travel by rugged paths, and through valleys as well as over mountains. Doubt must necessarily succeed often to apparent certainty, and must again give place to a certainty of a higher order; such is the imperfection of our faculties, that the descent from conviction to hesitation is not uncommonly as salutary, as the more agreeable elevation from uncertainty to demonstration. An example of such alternations may easily be adduced from the history of chemistry. How universally had phlogiston once expelled the aërial acid of Hooke and Mayow. How much more completely had phlogiston given way to oxygen! And how much have some of our best chemists been lately inclined to restore the same phlogiston to its lost honours! although now again they are beginning to apprehend that they have already done too much in its favour. In the mean time, the true science of chemistry, as the most positive dogmatist will not hesitate to allow, has been very rapidly advancing towards ultimate perfection."

"The calcination of a body is... the exposing of it to the action of fire, to produce some change upon it."

"The principal effects of fire in chemical operations are to carry off the volatile principles, and to separate them from the fixed, or to occasion the combustion of inflammable matters. Hence it follows that bodies are calcined either to deprive them of some volatile principle, or to destroy their inflammable principle, and sometimes for both of these purposes."

"We have examples of the first kind of calcination, in exposing calcareous earths and stones to the fire, to convert them into quicklime, which is effected by the entire evaporation of the watery principle contained in this kind of earth."

"The calcination of ', of ', of ', and of several other Salts, by fire, which deprives them of the water necessary for their crystallization; the roasting of minerals, by which the fire carries off the sulphur, , and other volatile contents; ought to be referred to the first kind of calcination."

"We have an example of the second kind of calcination, by exposing imperfect metals to fire; by which they lose their inflammable principle, their form, and metallic properties, and are changed into earthy matters called Metallic es."

"It is necessary to observe, that this second calcination differs essentially from the first, as the changes produced by it upon imperfect metals are not effected by evaporation, but by decomposition and destruction of their phlogiston. It is therefore a combustion, and not a volatilisation of their inflammable principle."

"Hence it follows, that the first kind of calcination may succeed without the contact of air and in close vessels, although it is more quick and complete in open vessels, from a property of air, by which it greatly accelerates the evaporation of volatile bodies. ...But as the second kind of calcination is a true combustion, like that of all inflammable bodies, it requires all the conditions necessary for combustion, and particularly the free access of air."

"There are many bodies, in the calcination of which an evaporation of volatile parts happens, and also a destruction or deprivation of their inflammable principle, although without any sensible combustion of this latter. Such particularly are all combinations of imperfect metallic matters with vitriolic and s: when these bodies are exposed to fire, their acid evaporates, and at the same time carries off with it their inflammable principle. We have examples of this kind of calcination in exposing to fire Martial Vitriol and Bezoar Mineral."

"Hitherto chemists are not agreed upon the number of simple principles or elements, of which all corporeal substances are composed. ...Others believe that earth and phlogiston are those principles which are the constituent parts of all corporeal substances. The greatest number seem to admit only the peripatetic elements."

"It appears from all these Experiments, that in each of them phlogiston, the simple inflammable principle, is present. It is well known, that Air attracts the inflammable part of bodies, and deprives them of it: not only this may be seen from the above Experiments, but it also appears that in the transition of what is inflammable principle into the Air, a considerable part of the Air is lost; but that what is inflammable principle is the sole cause of this effect, is evident..."

"It likewise appears that a given quantity of Air can be united to or saturated as it were only by a certain quantity of phlogiston..."

"Air is composed of two different fluids, the one of which attracts not the phlogiston, and the other has the quality of attracting it, and this latter fluid makes between a third and a fourth of the whole bulk of the air."

"These experiments seem to prove, that the transition of phlogiston into the air diminishes not always its bulk; which however other experiments clearly indicate..."

"Certainly it is a remarkable circumstance to observe, that the phlogiston separated from bodies, either without or with a fiery motion, and united with air, always considerably diminishes the bulk of air."

"It might be objected that the lost air is still contained in the residuum of air which could not farther be united with the phlogiston; for finding that kind of air lighter than common air, it might be supposed that the phlogiston when united with this air made it less ponderous, which circumstance is already known from other experiments. However, since phlogiston is a substance, (which always supposes some weight,) I very much doubt whether this hypothesis be founded on truth."

"Many chemists, even at the present day, find it impossible to do without certain collective names, analogous to the word phlogiston, for processes which they regard as belonging to the same class, or determined by the same cause. But instead of choosing for this purpose words which designate things, as was the custom till the end of the seventeenth... century, (phlogiston means, for example, fire, or light, and heat), they employ, since the time of Berthollet, terms which designate what are called "forces.""

"To investigate the essence of a natural phenomenon, three conditions are necessary. We must first study and know the phenomenon itself, from all sides; we must then determine in what relation it stands to other natural phenomena; and, lastly, when we have ascertained all these relations, we have to solve the problem of measuring these relations, and the laws of mutual dependence; that is, of expressing them in numbers. ...In the first period of chemistry, all the powers of men's minds were devoted to acquiring a knowledge of the properties of bodies; it was necessary to discover, observe, and ascertain their peculiarities. This is the alchemistical period. The second period embraces the determination of the mutual relations or connexions of these properties; and this is the period of phlogistic chemistry. In the third period, in which we now are, we ascertain by weight and measure, and express in numbers, the degree in which the properties of bodies are mutually dependent. The inductive sciences begin with the substance itself; then come just ideas; and lastly, mathematics are called in, and, with the aid of numbers, completes the work."

"We are... bound to attach the greatest importance to the preliminary step taken by Lavoisier, who is even more justly called the father of modern chemistry than Kepler is called the father of modern astronomy. The exact claims of Lavoisier to this important place in the history of chemistry have been variously stated: ...since his time, and greatly through his labours, the quantitative method has been established as the ultimate test of chemical facts; the principle of this method being the rule that in all changes of combination and reaction, the total weight of the various ingredients—be they elementary bodies or compounds—remains unchanged. The science of chemistry was thus established upon an exact, a mathematical basis. By means of this method Lavoisier, utilising and analysing the results gained by himself and others before him, notably those of Priestley, Cavendish, and Black, succeeded in destroying the older theory of combustion, the so-called phlogistic theory."

"In the time of Lavoisier, and preeminently through his exertions, this vague and unmeasurable principle phlogiston was eliminated from the laboratory and the textbooks: quantities took the place of indefinable qualities, and numerical determinations increased in frequency and accuracy. The vague phlogistic theory, which contained a germ of truth, but one which at that time could not be put into definite terms, had helped to gather up many valuable facts and observations: these were collected and restated in a new and precise language. It has been said that every science must pass through three periods of development. The first is that of presentiment, or faith; the second is that of sophistry; and the third is that of sober research."

"Even before the appearance of The Sceptical Chemist there was a growing conviction that the old hypotheses as to the essential nature of matter were inadequate and misleading. ...[T]he four "elements" of the Peripatetics had become merged into the tria prima—the "salt," "sulphur," and "mercury"—of the Paracelsians. As the phenomena of chemical action became better known... the conception of the tria prinui, as understood by Paracelsus and his followers, was incapable of being generalised into a theory of chemistry. Becher, while clinging to the conception of three primordial substances as making up all forms of matter, changed the qualities hitherto associated with them. According to the new theory, all matter was composed of a mercurial, a vitreous, and a combustible substance or principle, in varying proportions, depending upon the nature of the particular form of matter. When a body was burnt or a metal calcined, the combustible substance—the terra pinguis of Becher—escaped."

"This attempt to connect the phenomena of combustion and calcination with the general phenomena of chemistry was still further developed by Stahl, and was eventually extended into a comprehensive theory of chemistry, which was fairly satisfactory so long as no effort was made to test its sufficiency by an appeal to the balance."

"The theory of phlogiston was originally broached as a theory of combustion. According to this theory, bodies such as coal, charcoal, wood, oil, fat, etc., burn because they contain a combustible principle, which was assumed to be a material substance and uniform in character. This substance was known as phlogiston."

"All combustible bodies were to be regarded... as compounds, one of their constituents being phlogiston: their different natures depended partly upon the proportion of phlogiston they contain, and partly upon the nature and amount of their other constituents."

"A body, when burning, was parting with its phlogiston; and all the phenomena of combustion—the flame, heat, and light—were caused by the violence of the expulsion of that substance."

"Certain metals—as, for example, —could be caused to burn, and thereby to yield earthy substances, sometimes white in colour, at other times variously coloured. These earthy substances were called calces, from their general resemblance to lime."

"Other metals, like lead and mercury, did not appear to burn; but on heating them they gradually lost their metallic appearance, and became converted into calces. This operation was known as . In the act of burning or of calcination phlogiston was expelled. Hence metals were essentially compound: they consisted of phlogiston and a calx, the nature of which determined the character of the metal. By adding phlogiston to a calx the metal was regenerated. Thus, on heating the calx of zinc or of lead with coal, or charcoal, or wood, metallic zinc or lead was again formed. When a candle burns, its phlogiston is transferred to the air; if burned in a limited supply of air, combustion ceases, because the air becomes saturated with phlogiston."

"Respiration is a kind of combustion whereby the temperature of the body is maintained. It consists simply in the transference of the phlogiston of the body to the air. If we attempt to breathe in a confined space, the air becomes eventually saturated with the phlogiston, and respiration stops."

"The colour of a substance is connected with the amount of phlogiston it contains. Thus, when lead is heated, it yields a yellow substance (); when still further heated, it yields a red substance (red lead). These differences in colour were supposed to depend upon the varying amount of phlogiston expelled."

"The doctrine of phlogiston was embraced by nearly all Stahl's German contemporaries, notably by Marggraf, Neumann, Eller, and [Johann Heinrich] Pott. It spread into Sweden, and was accepted by Bergman and Scheele; into France, where it was taught by Duhamel, Rouelle, and Macquer; and into Great Britain, where its most influential supporters were Priestley and Cavendish. It continued to be the orthodox faith until the last quarter of the eighteenth century, when, after the discovery of oxygen, it was overturned by Lavoisier."

"During the sway of phlogiston chemistry made many notable advances... in spite of it. ...[U]ntil the time of Lavoisier few if any investigations were made with the express intention of testing it, or of establishing its sufficiency. When new phenomena were observed the attempt was no doubt made to explain them by its aid, frequently with no satisfactory result. Indeed, even in the time of Stahl facts were known which it was difficult or impossible to reconcile with his doctrine; but these were either ignored, or their true import explained away."

"It is commonly stated that the exception is a proof of the rule. The history of science can show many instances whereby the rule has been demolished by the exception. Little facts have killed big "theories, even as a pebble has slain a giant. During the reign of phlogiston a few of such facts were not unknown at least to some of the better informed of Stahl's followers."

"Some of the alchemists had discovered that a metal gained, not lost, weight by . This was known as far back as the sixteenth century. It had been pointed out by Cardan and by Libavius. Sulzbach showed that such was the case with mercury. Boyle proved it in the case of tin, and Rey in that of lead. Moreover, as knowledge increased it became certain that Stahl's original conception of the principle of combustion as a ponderable substance he imagined, with Becher, that it was of the nature of an earth was not tenable. The later phlogistians were disposed to regard it as probably identical with . But even hydrogen has weight, and facts seemed to require that phlogiston, if it existed at all, should be devoid of weight."

"Towards the latter half of the eighteenth century clearer views began to be held concerning the relations of atmospheric air to the phenomena of combustion and of calcination; many half-forgotten facts relating to these phenomena were recalled, and the inconsistencies and insufficiency of phlogiston as a dogma became gradually manifest. Three cardinal facts conspired to bring about its overthrow—the isolation of oxygen by Priestley; the recognition by him of the nature of atmospheric air, and of the fact that one of its constituents is oxygen; and, lastly, the discovery by Cavendish that water is a compound, and that its constituents are oxygen and . The significance of these facts was first clearly grasped by Lavoisier, and to him is due the credit of their true interpretation. By reasoning and experiment he proved conclusively that all ordinary phenomena of burning are so many instances of the combination of the oxygen of the air with the combustible substance; that calcination is a process of combination of the oxygen in the air with the metal, which thereby increases in weight by the amount of oxygen combined. Water no longer a simple substance is formed by the union, weight for weight, of oxygen and hydrogen. ...The phlogiston myth was thus exploded."

"Inspired by Lavoisier, a small band of French chemists Berthollet, Fourcroy, Guyton de Morveau thereupon set to work to remodel the system of chemistry and to recast its nomenclature so as to eliminate all reference to phlogiston. The very names "oxygen," "hydrogen," "nitrogen," corresponding respectively to the "dephlogisticated air," "phlogiston," and "phlogisticated air" of Priestley, were coined by the new French school."

"For a time le principe oxygine was regarded by this school in much the same relation as phlogiston was regarded by Stahl and his followers. The one fetich was exchanged for the other. The combustible principle—phlogiston—was renounced for the acidifying principle—oxygen. The new chemistry for a time centred itself round oxygen, just as the old chemistry had centred itself round phlogiston. The views of the French school met with no immediate acceptance in Germany, the home of phlogistonism, or in Sweden or England, possibly owing, to some extent, to national prejudices. The spirit of revolution, even although it might be an intellectual revolution, had not extended to these countries. Priestley, Cavendish, and Scheele could not be induced to accept the new doctrine. It was, however, accepted by Black, and its principles taught by him in Edinburgh; and before the end of the century it had practically supplanted phlogistonism in this country. Some of those who, like Kirwan, had energetically opposed the new theory ended by enthusiastically embracing it. Its introduction into Germany was mainly due to the influence of Klaproth."

"Van Helmont adds a... criticism to the Paracelsian theory. The tria prima play no role in disease, as they cannot be isolated from the living body. Paracelsus, he believes, was mistaken in assuming that the salt in urine was one of the tria prima, when in fact it is only salt water that has not yet been separated into its components. In fact, the tria prima cannot be obtained from living things at all; only by the destruction of the living principle... Hence diseases cannot be caused by the three principles... Surprisingly... he employs the tria prima in his theory... Van Helmont first postulates that water presents itself in four distinct states: ice, water, vapour and Gas... [and] contends that water is formed of 'atoms', which in turn are made up of the three principles (mercury, salt, and sulphur) in different spatial arrangements within the atom. These... give water both its resiliance and diversity of character."

"Tria Prima. The three elements of the alchemists, their salt, sulphur, and mercury: the first of which appears to have denoted whatever remained fixed in the fire; the second, whatever was inflammable; and the third, whatever was neither fixed nor inflammable, but rose in vapour without being burned."

"Alchemical theory was essentially static throughout the medieval period. ...Paracelsus was the herald of a new era, an era of . His contribution to alchemical theory lay in the addition to sulphur and mercury of a third principle, which he called 'salt.' Materially this was recognised as the principle of uninflammability and fixidity. ...[T]he tria prima, or three 'hypostatical principles' could be interpreted in either a material or a spiritual sense. In the words of Paracelsus himself: 'Know, then, that all the seven metals are born from a threefold matter... Mercury is the spirit, Sulphur is the soul, and Salt is the body... the soul... unites those two contraries, the body and spirit, and changes them into essence.' ...similar to the material effect of the liquid menstruum, or Hermetic Stream, in uniting sophic sulphur and sophic mercury to produce the Philospher's Stone."

"Since a great part of those Learned Men, especially Physicians who have discerned the defects of the vulgar Philosophy, but are not yet come to understand and relish the Corpuscularian, have slid into the Doctrine of the Chymists; and since the Spagyrists are wont to pretend to make out all the Qualities of bodies from the Predominancy of some one of their three Hypostatical Principles, I suppose it may both keep my opinion from appearing too presumptuous, and (which is far more considerable) may make way for the fairer Reception of the Mechanical Hypothesis about Qualities, if I here intimate (though but briefly and in general) some of those defects, that I have observed in Chymists Explications of Qualities."

"Now a man need not be very conversant in the writings of Chymists to observe, in how Laxe, Indefinite, and almost Arbitrary Senses they employ the Terms of Salt, Sulphur and Mercury; of which I could never find that they were agreed upon any certain Definitions or setled Notions; not onely differing Authors, but not unfrequently one and the same, and perhaps in the same Book, employing them in very differing senses."

"And first the Doctrine that all their Theory is grounded on, seems to me Inevident and undemonstrated, not to say precarious."

"It is somewhat strange to me, that neither the Spagyrists themselves, nor yet their Adversaries, should have taken notice that Chymists have rather supposed than evinced, that the Analysis of bodies by fire, or even that at least some Analysis is the onely instrument of investigating what Ingredients mixt bodies are made up of, since in divers cases That may be discovered by Composition as well as by Resolution; as it may appear, that consists of metalline parts (whether Martial, or Venereal, or both) associated by Coagulation with ones, one may, I say, discover this as well by making true Vitriol with Spirit (improperly called Oil) of Sulphur, or that of Salt, as by distilling or Resolving Vitriol by the fire."

"But I will not... trouble you with what I have largely discoursed in the Sceptical Chymist, to call in question the grounds on which Chymists assert, that all mixt bodies are compounded of Salt, Sulphur, and Mercury. For it may suffice me now to tell you that, whatsoever they may be able to obtain from other bodies, it does not appear by Experience, which is the grand, if not the onely, Argument they rely on, that all mixt bodies that have Qualities consist of their tria prima, since they have not been able, that we know, truly, and without new Compositions, to resolve into those three, either Gold, or Silver, or Crystal, or Venetian Talck, or some other bodies, that I elsewhere name; & yet these bodies are endowed with divers Qualities, as the two former with Fusibleness and Malleability, and all of them with Weight and Fixity; so that in these and the like bodies, whence Chymisats have not made it yet appear, that their Salt, Sulphur and Mercury, can be truly and adequately separated, 'twill scarce be other than precarious to derive the malleableness, colour, and other Qualities of such bodies from those Principles."

"The doctrine of the four elements seems to have continued undisputed till the time of the alchemists. These men, better acquainted than the ancient philosophers with the analysis of bodies, became convinced of the inadequacy of that doctrine to explain all the phenomena which were presented to their view. Hence they substituted in its stead a theory of their own; namely, that all bodies are composed of three elements, salt, sulphur, and mercury, which they distinguished by the appellation of the tria prima. To these principles, which were embraced by succeeding writers, Paracelsus added two more, phlegm and caput mortuum."

"The alchemists seem to have attached only a very indefinite meaning to the terms salt, sulphur, and mercury: since by salt they appear to have designated every thing which is fixed in the fire; all inflammable substances they denominated sulphur; and every substance which flies off without burning, mercury."

"In conformity with this theory they maintained, that all bodies may be decomposed by means of fire into these three principles; the salt remains behind fixed, the sulphur takes fire, and the mercury flies off in the form of smoke. The phlegm and caput mortuum of Paracelsus were the water and earth of the ancient philosophers."

"Boyle attacked this hypothesis in his Sceptical Chemist, and several of his other publications: proving that under each of the terms salt, sulphur, mercury, phlegm, and earth are comprehended substances of very different properties; that all bodies are not composed of these principles; and that the principles themselves are not elements, but compounds."

"From this epocha the hypothesis of the tria prima seems wholly to have been abandoned: whilst a very different doctrine was proposed by Beccher in his Physica Subterranea [1669], and to which we are perhaps indebted for the present advanced state of chemical science; since he was the first to point out chemical analysis as the only true method of ascertaining the elements of bodies. According to his doctrine, all terrestrial bodies are composed of water, air, and three earths; viz. the fusible, the inflammable or sulphureous, and the mercurial. The three earths, combined in nearly equal proportions, compose the metals: when the proportion of mercurial earth is very small, they compose stones; when the fusible predominates, the resulting compounds are the precious stones; when the sulphureous predominates, and the fusible is deficient, the compounds are the calorific earths: fusible earth and water compose an universal acid, very much resembling sulphuric acid, from which all other acids derive their acidity; water, fusible earth, and mercurial earth, constitute common salt; sulphureous earth and the universal acid form sulphur. Such was the theory of Beccher, which was afterward considerably modified by Stahl."

"The "Chemico-physical Doubts and Paradoxes" raised by Boyle "touching the experiments whereby vulgar Spagyrists are wont to endeavour to evince their Salt, Sulphur, and Mercury to be the true Principles of Things," eventually sealed the fate of the doctrine of the tria prima, and of the tenets of the school of Paracelsus."

"In this treatise Boyle sets out to prove that the number of the peripatetic elements or principles hitherto assumed by chemists is, to say the least, doubtful."

"The words "element" and "principle" are used by him as equivalent terms, and signify those primitive and simple bodies of which compounds may be said to be composed, and into which these compounds are ultimately resolvable."

"He concludes... that the Paracelsian elements—their "salt," "sulphur," and "mercury"—are not the first and most simple principles of bodies; but that these consist, at most, of concretions of corpuscles or particles more simple than they, and possessing the radical and universal properties of volume, shape, and motion."

"[Paracelsus] arranged the several parts of man, his own universal elements, and the Aristotelian elements in triplets, thus :—"

"[T]he writings and labours of the alchemists were both extensive and important. ...[T]heir studies, although misdirected, were not... haphazard. The alchemists had a definite, and... logical, system of philosophy... [T]hey recognised—(1) the unity of matter; (2) the three principles—philosophical mercury, sulphur, and salt; (3) the four elements—fire, air, water, and earth; and (4) the seven metals—gold, silver, mercury, copper, , tin, and ."

"The original matter, or ', was called by various names—universal substance, seed, chaos. Although matter changes its form, it cannot be destroyed. ...In its nature the ' was assumed to be a liquid, containing everything in posse, but nothing in esse."

"All metals and minerals consist of certain principles. These were at first called "mercury" and "sulphur," not the ordinary substances... but a philosophical mercury and a philosophical sulphur. ...At a later period the alchemists added a philosophical salt, or a philosophical arsenic, but they never ascribed to these the importance they attached to the other two principles."

"Traces of these ancient conceptions are still to be recognised in the word "quick-silver," that is living silver, a literal translation of argentum vivum. A term "quick-sulphur" (sulphur vivum) was also in use, but it has long since disappeared."

"The mercury of a metal... represented its lustre, volatility, fusibility, and malleability; the sulphur of the metal, its colour, combustibility, affinity, and hardness."

"The salt of the was merely a means of union between the mercury and the sulphur, just as the vital spirit in man unites soul and body. It was doubtless devised to impart a triple form to the idea, in conformity with the method of the theological schoolmen."

"Mercury, sulphur, and salt were not three matters, but one, derived from the '."

"[W]hen an alchemist converted a metal into its oxide, or, as they expressed it, "made a " of it, he thought he had volatilised its mercury and fixed its sulphur. When he distilled ordinary mercury and found a solid residue in the , he called it the "sulphur" of mercury; when he found a sublimed product in the receiver (mercury bichloride), he termed it the "mercury" of mercury or "corrosive sublimate.""

"The more logical mind of Artephius Longaevus introduced a modification of this theory. He distinguished two properties in a metal—the visible and the occult. The former, comprehending its colour, lustre, extension, and other properties visible to the eye, he called its "sulphur"; the latter, comprehending its fusibility, malleability, volatility, and other properties not visible until after... special treatment, he called its "mercury.""

"Practically... there was little difference in the application of these diverse theories regarding the three principles."

"At a still later date [post-16th century] it was argued that exact and natural sciences proceed by induction and deduction, and occult and spiritual sciences by analogy. Following out this line of thought the alchemists produced the following remarkable trilogy:—"

"Each of these was a trinity in unity, and a unity in trinity. In each world was a distinct design,—in the material, the perfection of the metals; in the human, the perfection of the soul; in the divine, the contemplation of the Deity in His splendour."

"These mystic alchemists interpreted the three principles in their own fashion. Mercury, the passive and female principle, was matter; sulphur, the active and male principle, was force; and salt, the middle term in the proposition, was movement, which applied force to matter. Or, expressed in another shape, mercury was the subject: sulphur, the cause; and salt, the effect. Symbolically, the theory was represented by an equilateral triangle, in one angle of which was the sign of sulphur or force; in the second, the sign of mercury or matter; and in the third, the sign of salt or movement."

"Aristotle had considered metals to be formed by the combination of moist and dry exhalations, and in the Jabirian works these... are... vapours of mercury and sulphur. The cause of the different metals was the... quality of the sulphur... The term sulphur ...as a component of metals probably referred to a volatile combustible material to which no... substance corresponded exactly. Likewise mercury... may... have been... an approximation to the other volatile liquid component of metals. ...The notion that metals contained a combustible principle persisted, and... provided the inspiration for the phlogiston theory."

"The Jabirian alchemists... believed that metals were ultimately composed of the four Aristotelian elements earth, water, air and fire... A base metal had to be treated with a medicine or elixir to adjust... qualities... with the proportions of gold. ...[Q]ualities of heat, cold, moisture and dryness could each be separated in pure form. ...First they subjected various organic materials to dry distillation... which often resulted in... a volatile combustible... (air), a liquid (water), a combustible tarry material (fire) and a dry residue (ash). [Each of] [t]hese elements were supposed... composed of two qualities, and... could be isolated by... purification. Thus water... could be converted into pure cold by repeated distillation... and further [distillations] in the presence of a drying agent. The resulting pure cold... a brilliant white solid."

"Paracelsus made an important contribution to chemical theory. He extended the sulphur-mercury theory of the Islamic chemists by adding a third principle... salt. Thus, when wood burned, the combustible component was identified with sulphur, the volatile component with mercury and the ashes... with salt. The composition of all substances could be expressed in terms of these three principles, or tria prima. As in previous theories... [these] were not... common materials... but rather... essential qualities."

"Alkalimetry. ...The object of alkalimetrical operations is to determine the quantity of caustic alkali, or of carbonate of alkali, contained in the potash or soda of commerce. These operations are simple, accurate, rapid, and easy; they may be said to consist in pouring on a weighed portion of the sample of potash or of soda under examination, a certain quantity of an acid of a known strength, until the alkali is saturated, that is to say, until the neutralizing point is hit, which is ascertained by means of ..."

"Alkali. (Arabic, al Kali.) A name applied to a well-defined class of bodies characterized by the following properties. They turn red blue, completely neutralize s, they are soluble in water, and their solutions exert a caustic action upon animal matter. The alkalies proper are the oxides of , , , and cæsium. To these must be added the compound alkali , the oxide of the hypothetical metal , which used to be called the volatile alkali, in contradistinction to potash and soda, which were called fixed alkalies. The alkaline earths are the oxides of , , , and . The oxides of some other metals, such as silver, , and , are also somewhat soluble in water, and possess slight alkaline properties."

"Alkali. Alkaline Earth. The class of alkalis is amongst the most antient in chemical science, and one which has stood its ground through all the changes occasioned by modern discoveries, though with some modification."

"The original application of the term alkali (which is of Arabian origin) was to express the acrid saline residue left in the ashes of the plant kali, after its combustion in open air. This was also very early known to the Greeks and Romans; by the latter termed, lixivial, which term is still retained, lixivium, or ley, meaning properly the soluble salt extracted out of vegetable ashes by the addition of water. From the circumstance of the ashes being the fixed or unvolatilized part of the plant, the rest having been dissipated by the combustion, the lixiviary salt was also called fixed alkali, a term still in universal use."

"The proper fixed alkalies are of two kinds, the vegetable or ', and the mineral or soda; the latter is found often native in immense quantities being the basis of rock salt, and is also the principal saline residue of many plants growing on the sea shore; and the former is contained in, and almost entirely procured from, the ashes of vegetables in general, not growing contiguous to the sea. Under the articles Potash and Soda, and Carbonat of Potash and Soda, these most important Salts are fully described."

"Again, as the volatile ammoniacal salt most curable from most animal matter (also of great antiquity) was found to agree with the other alkalies in taste, and in many chemical properties, though not in fixity, this ammoniacal salt was also termed an alkali, but volatile, in opposition to the two former, which remain unaltered in very considerable heat, and are therefore, comparatively, fixed. The volatile alkali is described under the article ."

"Of late years, some of the earths (especially s and strontian, which were unknown to antiquity) having been found to possess alkaline properties in no ambiguous degree, these have been by some chemists absolutely associated with the alkalies; by others have received the term alkaline earths, to express this resemblance which in the two above mentioned almost amounts to identity of properties; but in the two others, lime and magnesia, the agreement is only partial."

"As it is but of little consequence which arrangement be adopted, provided an uniformity be observed, we have throughout the present work restricted the term alkali, to the three antient salts of that name; the two fixed, and soda, and the volatile . Under the appellation alkaline earth, we include the following, s, Strontian, Lime, and Magnesia."

"We shall now enumerate the properties usually described as belonging to alkalies, distinguishing how far they are possessed by the three salts and the four earths above enumerated."

"The taste of an alkali is acrid, burning, and nauseous. It acts with so much energy and rapidity on the tongue, as to destroy, if concentrated, the skin of the part which it touches, and hence its extreme causticity. The three alkalies possess this in the highest degree, more rapidly soluble than the earths, and the latter only s, strontian, and lime, exhibit this corrosive taste, magnesia being absolutely insipid."

"All the alkalies, except ammonia, are without smell, or nearly so, a particular urinous odor however arises during the solution with heat, of the other alkalies and earths, magnesia excepted."

"(whose natural state when uncombined, is that of a gas) magnesia, and probably lime, are incapable of crystallization, the other alkalies and alkaline earths are crystallizable."

"Only the volatile alkali has been decomposed. The others have often been suspected to be also compound, and with some probability, but they have hitherto eluded the attempts of chemists to decompose them."

"alone is volatilized by the application of any degree less than a red heat; when fully red, or at a heat about that of melting copper, the fixed alkalies begin to be dissipated in dense vapours, but the alkaline earths resist any but the extremest degree of heat which has ever been applied."

"The alkalies are extremely soluble in water, s and strontian in considerable quantity, lime, sparingly; magnesia scarcely at all."

"They possess the strongest affinity for s of all other bodies, uniting with them generally to such a degree as to produce perfect neutralization, or such a state of union, that the characteristic properties of both acid and alkali are lost, and new ones acquired. Most of the combinations with acids are considerably soluble in water, and all crystallizable with more or less ease."

"The comparative force of affinity for the individual acids possessed by the alkalies and alkaline earths, is not uniformly the same, but generally one or two of the earths stand the highest in force. The affinity of them all for acids is superior to that of the metallic oxyds, and hence they decompose lic solutions."

"They all have their peculiar alkaline properties highly modified and lessened, but not entirely taken away, by union with . Hence the states of mild and caustic, the former expressing union with this acid; the latter, the contrary; which obtains in all these substances, though in magnesia alone the difference is scarcely perceptible as it regards the sensible properties."

"They all unite with sulphur forming compounds soluble in water, of a peculiar fœtid smell, ing the white metals, called sulphurets or hydro-sulphurets, according to circumstances."

"They all unite with the fixed oils and animal fats, either into a true soap, or into a saponaceous compound. The fixed alkalies unite more perfectly with the oils, and the alkaline are the only true soaps, being soluble in water. The earthy mixtures with oil are indeed strongly combined, but are insoluble in water."

"s will combine directly with oils, as M. Vauquelin has found, and when heated with animal matter, will cause it to give out a large quantity of , and will reduce it to a kind of saponaceous soluble mass."

"When in solution in a red heat (from which of course the volatile alkali is excepted) they dissolve into that beautiful transparent compound called glass. This property of is the strongest in the alkalies, but has been found by M. Vauquelin to be very powerful in strontian and s."

"With the exception of magnesia, they all powerfully corrode the soft parts of vegetables, and especially animals. Bulk for bulk, the fixed alkalies are by far the most powerful and active in this respect."

"Lastly they all produce certain changes on some vegetable colours, and this test is perhaps the most striking of all above enumerated, since it is possessed by all without exception, though with some variety. The colours of many plants are changed by them to , of which the syrup or tincture of violets, affords a ready instance; many of the reds, such as that of logwood and , are changed into violet; and the of a great many plants, such as , , or root, is changed to a , or dirty brick red."

"The latter change seems to be confined to the alkalies when both are carbonated, so that the change of turmeric-yellow into red will distinguish the presence of a carbonated alkali from that of an alkaline earth, held in solution by an excess of carbonic acid. But when pure or caustic, the change is the same in both."

"The power of all these substances over vegetable colours is very great in proportion to the quantity used, and it should be remarked, that in this instance also, acids and alkalies, or alkaline earths, are in direct opposition to each other, the acid restoring the colour to its original state, after it has been changed by the alkali, and vice versa. Hence a single coloured vegetable may be made a very delicate test for both acids and alkalies; , for example, previously reddened by acids, will be changed into purple by alkalies, and purpled litmus will detect an acid by becoming red."

"It appears therefore that there is scarcely a single characteristic except the change of certain colours, that will apply equally to all the alkalies and akaline earths, but yet the general resemblance is so great as to justify this classification."

"Magnesia alone has the least claim to the title of an alkaline earth, and yet its affinity to acids is strong, and its power of changing some of the vegetable colours is very considerable."

"About 1750 Black went to Edinburgh University to complete his medical studies... The attention of medical men was directed at this time to the action of lime-water as a remedy for stone in the bladder. All the medicines which were of any avail in mitigating the pain attendant on this disease more or less resembled the "caustic ley of the soap-boilers" (...caustic potash or soda). These caustic medicines were mostly prepared by the action of quicklime on some other substance, and quicklime was generally supposed to derive its caustic, or corrosive properties from the fire which was used in changing ordinary into quicklime. When quicklime was heated with "fixed alkalis" (i.e. with potassium or ), it changed these substances into caustic bodies which had a corrosive action on animal matter; hence it was concluded that the quicklime had derived a "power"—or some said had derived "igneous matter"—from the fire, and had communicated this to the fixed alkalis, which thereby acquired the property of corroding animal matter."

"Black thought that he might be able to lay hold of this "igneous matter" supposed to be taken by the from the fire; but he found that limestone loses weight when changed into quicklime. He then dissolved limestone (or chalk) in spirits of salt (), and compared the loss of weight undergone by the chalk in this process with the loss suffered by an equal quantity of chalk when strongly heated. This investigation led Black to a fuller study of the action of heat on chalk and on "mild magnesia" (or as we now say, )."

"[In 1755 Black] presented his thesis on "Magnesia Alba, Quicklime and other Alkaline Substances," which contained the results of what is probably the first accurately quantitative examination of a chemical action which we possess."

"Black prepared mild magnesia () by boiling together solutions of Epsom salts () and fixed alkali (). He showed that when mild magnesia is heated—"

"He then strongly heated a weighed quantity of mild magnesia in a connected with a receiver; a few drops of water were obtained in the receiver, but the magnesia lost six or seven times as much weight as the weight of the water produced."

"Black then recalls the experiments of Hales, wherein airs other than common air had been prepared, and concludes that the loss of weight noticed when mild magnesia is calcined is probably due to expulsion, by the heat, of some kind of air."

"Dissolving some of his mild magnesia in he noticed that effervescence occurred, and from this he concluded that the same air which, according to his hypothesis, is expelled by heat, is also driven out from the mild magnesia by the action of acid. He then proceeded to test this hypothesis."

"One hundred and twenty grains of mild magnesia were strongly calcined; the calcined matter, amounting to seventy grains, was dissolved in dilute oil of vitriol, and this solution was mixed with common fixed alkali (). The solid which was thus produced was collected, washed and weighed; it amounted to a trifle less than one hundred and twenty grains, and possessed all the properties—detailed by Black—of the original mild magnesia. But this is exactly the result which ought to have occurred according to his hypothesis."

"The next step in the investigation was to collect the peculiar air which Black had proved to be evolved during the calcination of mild magnesia."

"To this substance he gave the name of "fixed air," because it was fixed or held by magnesia. Black established the existence of this air in the expired breath of animals, and also showed that it was present in the air evolved during vinous fermentation. He demonstrated several of its properties; among these, the fact that animals die when placed in this air."

"Black did not hamper the advance of chemistry by finding a "principle of alkalinity;" but neither did he give a full explanation of the fact that certain bodies are alkaline while others are not. He set himself the problem of accurately determining the differences in composition between burnt (or caustic) and unburnt (or mild) alkali, and he solved the problem most successfully. He showed that the properties of mild alkalis differ from those of caustic alkalis, because the composition of the former differs from that of the latter; and he showed exactly wherein this difference of composition consists, viz. in the possession or non-possession of fixed air."

"Strange we may say that this discovery did not induce Black to prosecute the study of caustic alkalis: surely he would have anticipated Davy, and have been known as the discoverer of and ."

"In the time of Stahl the name "salt" was applied... to the substance produced by the union of an acid with an alkali; but the same word was used by the alchemists with an altogether different signification."

"The chemical histories of the three classes of compounds s, s, and bases, are closely interwoven. Black's quantitative experiments led to the division of alkalis and earths into two classes; mild alkalis and mild earths, and caustic alkalis and caustic earths or quicklimes."

"[A]t about the time of the discovery of oxygen, salts were thought of as compounds formed by the addition of s to bases which were generally alkalis or earths; if a mild alkali or a mild earth was the basis, fixed air escaped; if a caustic alkali or earth was the basis, fixed air was not produced."

"Besides being built on the bases of alkalis and earths, salts could be formed by adding s to the calces of metals. When Lavoisier had proved calces to be s, the theory of the composition of acids and salts was almost complete. Analogy indicated that the alkalis and the earths must be oxides of metals. If experimental investigation should confirm this supposition, the edifice was finished."

"Alkali (Arabic = the ash). This term was originally applied to the ashes of sea-plants; but it was soon extended to include substances which, like the ash of sea-weed, easily dissolved in water, forming solutions which had a soap-like action on the skin, affected the colour of plants, and reacted with acids with effervescence and the production of new substances wherein neither the properties of the acids nor those the alkalis were prominent."

"Van Helmont and his successors recognised two kinds of alkali, fixed and volatile; Duhamel, in 1736, divided fixed alkali into two classes, vegetable (), and mineral alkali (soda)."

"Little or nothing was known regarding the composition of alkali until the year 1755 when Black (on the occasion graduating as MD at Edinburgh) published dissertation on 'Magnesia Alba, Quicklime, other Alkaline Substances.' Magnesia alba dissolved in s with effervescence; but after being strongly heated no effervescence attended the solution of this alkali."

"The notion of (end of 15th and beginning of 16th century), that lime when burnt combined with 'matter of fire,' had been accepted by many as an explanation of the difference in the behaviour towards acids of burnt and unburnt lime. If this explanation applied to magnesia it should be possible perhaps to get hold of this 'matter of fire,' which combined with the magnesia alba when that body was heated. But Black found that a given mass of magnesia alba weighed more than the calcined magnesia obtained from it. Hence something was lost instead of gained during the process of heating. This something proved on further quantitative examination to be a gas different from common air; to it Black gave the name of fixed air."

"The effervescence or non-effervescence of alkalis with acids was proved by Black to accompany the presence or absence of fixed air (). From this time a distinction was clearly drawn between alkalis, which dissolved in acids without effervescence, and carbonated alkalis, the solution of which in acids was accompanied by the escape of carbonic acid gas. It was recognised that whether a caustic or a carbonated alkali dissolved in an acid, the body which remained in solution, and which had no close resemblence either to the acid or the alkali, was one and the same."

"The properties of the alkalis were supposed by the older chemists to be due to a 'principle of alkalinity,' or sometimes to a 'principle of saltness,' which latter principle was common to acids, alkalis, and the products of their mutual action, i.e. salts."

"Closely allied to, and sometimes regarded as identical with, the alkalis, was the group of earths. These bodies were known to neutralise acids and affect colouring matters like alkalis, but they were much less soluble in water than the alkalis."

"It was taught by some chemists that an alkali is hidden in every earth, and by others that an alkali is an earth refined by the presence of acid and combustible matter. Black's exact quantitative investigations tended to disparage all such explanations as these; but it yet remained to find the precise composition the alkalis and the earths."

"Lavoisier thought that these bodies must be compounds; but, as he had no means of proving this, he classed them with the elements, while suggesting that the earths were probably compounds of oxygen with unknown metals."

"In 1807 Davy decomposed two alkalis, and soda, by passing an electric current through these substances when molten; and a year later he succeeded, by the same agency, in separating the earthy bodies lime, baryta, and strontia, into oxygen and, in each case, a metal."

"The name alkali is now generally applied to the compounds of and oxygen with one or other of the five metals, , , , , cæsium (v. Alkalis, Metals of the); an aqueous solution of is also regarded as containing an alkali, viz. a compound of hydrogen and oxygen with the radicle ' (v. Ammonium Compounds)."

"The alkalis are classed with the s, i.e. compounds of hydrogen and oxygen with a third element, rather than with the hydrates, i.e. compounds of water with an oxide or a salt. (v. Hydrates)."

"The general formula of the alkalis is written MOH rather than M2OH2O; M = Li, Na, K, Cs, Rb, or NH."

"The alkalis are very soluble in water; these solutions neutralise acids forming salts, and also precipitate most of the heavy metals from their solutions in the form of oxides or hydrated oxides; aqueous solutions of the alkalis act corrosively on animal and vegetable substances, and also alter the tint of many colouring matters."

"When moist, the alkalis, with the exception of , readily combine with to form s."

"Lithia is much less soluble in water than the other alkalis."

"The solid alkalis are not decomposed by the action of heat alone."

"By 3000 BCE the Sumerians, perhaps while heating copper to make it more malleable, had discovered that more copper could be retrieved from the fire if the metal were heated with certain types of dirt and stones—that is, certain earths. These earths were the metal s, and the process they discovered, ', reduced metal salts to pure metal by the action of in the fire. The process of changing metal salts into pure metal is known as reduction because the metal without the accompanying oxygen, , or of the salt weighs less than the ore. Eventually metal workers learned to distinguish various metal-bearing ores by color, texture, weight, flame color, or smell when heated (such as garlic odor of ores) and they could produce a desired material on demand."

"Pliny recorded processes involving metals, salts, , glass, mortar, soot, ash, and a large variety of s, earths, and stones. He describes the manufacture of charcoal; the enrichment of the soil with lime, ashes, and manure; the production of wines and ; varieties of s; plants of medicinal or chemical interest; and types of , gems and precious stones. He discusses some simple chemical reactions... and a crude indicator paper... of strips soaked in an extract of oak galls that changed color when dipped in solutions of blue vitriol... contaminated with ."

"The Earths are white, inodorous, tasteless, and uninflammable substances—non-conductors of electricity, insoluble in water, but soluble in one or more of the acids. Sp. gr. compared to that of water, not exceeding five to one. They are six in number; viz. silica, alumine, , gluttine, augustine, ytria; the consideration of which falls under their alphabetical order."

"What made silica so interesting was that... it did not seem to follow the established rules of chemical combination. In Smithson's time, chemical combination was... an acid combining with an alkali to produce a stable, neutral... "." Acids did not combine chemically with each other, nor did alkalis... [A] substance... found to contain an alkali... must also contain an acid—and vice versa. Bergman's description of the compounds containing earths as... "natural compositions of acids" meant... the other component must be alkaline—which the earths all seemed to be, except for silica."

"Earth is one of the four simple substances called elements, or primitive principles; because they are indeed the most simple of all those which enter into the combination of compound bodies. We cannot doubt, in particular, that the greatest part of the compounds which we can analyse contain earth as one of their principles; for after art has exhausted all its efforts to decompose them, a fixed and solid matter always remains, upon which no change can be produced; and this is what is generally called earth. It has the solidity, weight, fixity, and other principal properties of the mass of solid matter which forms the globe we inhabit, called also the earth."

"These general considerations are sufficient to convince us, that in nature a substance exists whose properties are different from those of fire, air, water; and which is, like these other substances, one of the elements of compound bodies. But a vague assertion like this does not satisfy chemists. Besides the ascertaining of the exigence of the different substances submitted to their examination, they require to know the properties of these substances in their greatest degree of purity and simplicity; but they have found much difficulty and uncertainty in investigating the essential properties of the purest and simplest terrestrial element."

"Earth is not found so pure as the other elements, fire, air, and water, which, though not entirely free from mixture, are however so pure, that we may certainly and easily discover their fundamental properties. These properties of each of these pure elements are so well ascertained, and so evident, that nobody has yet attempted to distinguish different kinds of fire, air, or water, notwithstanding the differences which may arise from the heterogeneous substances with which they are almost always mixed."

"But we cannot say the same of earth; for a considerable number of substances are called earths, because they possess the principal properties of the terrestrial element: but these substances, when examined more particularly, are always found to differ from each other so much in other respects, and to be so difficultly purifiable from heterogeneous matter, that we have not ascertained whether only one simple and elementary earth, or several ones essentially different, although equally simple, exist."

"The most general and most probable opinion is, that as only one kind of fire, of air, and of water, so only one kind of simple elementary earth, exists. Alchemists chiefly have endeavoured to discover this primary earth, not with an intention to ascertain its properties, but because they imagined that as gold is the purest of metals, the earth of which it is partly composed must be also the most pure; they have, therefore, searched every where for this earth, which they call pure earth and virgin earth. They have endeavoured to obtain it from dew, rain, the air, ashes of vegetables, animals, and several minerals: but it was impossible to find it in compound bodies; for we shall see that when once this element makes part of a compound body, it cannot be disengaged from the substances with which it has united."

"Some of the best philosophical chemists have rather chose to admit different kinds of elementary earths, than to investigate the nature of the most simple and elementary of all. Becker admits three principles, which he calls earths, namely, the vitrifiable, the inflammable, and the mercurial earth..."

"Mr. Pott, examining the principal natural earths, divides them into four kinds, the vitrifiable, the , the argillaceous, and the gypseous earths. This able chemist shew the essential properties of these four kinds of earths, without affirming that they are all equally simple, and without even determining which of them he considered as most simple."

"As earth is an element... it deserves an accurate investigation to discover which is the most simple and elementary of all the substances to which the name earth has been applied. ...considering, first, what are the essential properties by which earthy substances differ from other elements, and then by determining that earth to be the most pure and simple, which possesses these properties most eminently and decisively; for ...the more eminently any substance possesses these characteristic properties... the nearer it approaches to this element..."

"[A]ll the substances which may reasonably be considered as earthy... possess much greater weight, hardness, fixity, and infusibility, than any other element; for these qualities are insensible, or do dot exist, in the element of fire; they are in an exceedingly small degree in the air, and are more sensible and considerable in water; but are infinitely less than in any thing which can be considered as earth. Hence... the qualities above-mentioned are the distinguishing and characteristic essential properties of the earthy element. But these qualities are not so eminently united in any of those [earthy] substances... as in... vitrifiable earth. ...[T]hen ...this earth is the heaviest, hardest, most fixed, and most infusible, and even the most apyrous of all earths, when it is very pure; and also... the most homogeneous, the most simple, and elementary earth, as we shall prove by a more particular examination of its properties, and by a companion of these with the properties of the other earthy substances."

"We call that vitrifiable earth, the integrant parts of which when united form masses of matter or stones, absolutely white and colorless, much more transparent and hard than any other natural substances, and which suffers no alteration, or even fusion, by the strongest fire which we can apply to it."

"Amongst the hard stones called vitrifiable... few... strictly possess all the qualities... mentioned; because in very few... the vitrifiable earth is pure. Most of these stones, as hard pebbles of all kinds, sand, free-stone, s, , rock-crystal, and the stones called precious, are deficient in some... qualities required to constitute the purest vitrifiable earth. Some... are opake, or only semitransparent; others... colored; some... fusible by a great heat; and, lastly, others, although much harder than any other kind of stones, want the last degree of hardness; all which prove that they are mixed with heterogeneous substances, chiefly phlogistic, metallic, or even earthy, of a different kind."

"The purest of all the vitrifiable stones is the diamond, which is perfectly white, free from all color or stain, and transparent. This stone is also known to be the hardest of all, is absolutely apyrous, that is, incapable of receiving any alteration by the most violent heat. We, therefore, consider the matter of this stone as the purest, simplest, and most elementary earth that is known. The properties, then, of this stone, and of the other vitrifiable stones which resemble it, may give us notions of the properties of primary, elementary, unchanged earth. In this our opinion is conformable to that of the illustrious Stahl, who indeed admits the three earths of Becker; but, at the same time, corrects the theory of this chemist, by declaring that he only considers the first earth of Becker, or vitrifiable earth, as the proper terrestrial or earthy element."

"[T]he name vitrifiable earth... may produce false notions of the nature of these stones."

"[T]he epithet, vitrifiable is given, first, because some stones of this kind are, by means of their heterogeneous matters, capable of fusion and conversion into glass, without addition, and merely by the action of a very violent heat; and secondly, because other stones... require for their perfect fusion and vitrification a less quantity of flux, and a less degree of heat."

"In the second place, as all the earths and stones called vitrifiable have, notwithstanding their impurity, more hardness and transparency than others, and are fitter to communicate these good qualities to glass, they are employed preferably to any other earths in the composition, of glass, or artificial crystal. These are the only reasons why this kind of earth has been called vitrifiable. But we ought not from thence to conclude, that the earthy substance [i.e., the earth element or principle] which almost entirely composes them is more fusible and more vitrifiable than other earths: on the contrary... vitrifiable earth, when very pure, is of all earths the least fusible, and the least vitrifiable."

"I was present at a fine experiment made relatively to this subject. Some diamond powder was mixed with a sufficient quantity of fixed alkali to vitrify another earthy matter, and the mixture exposed to a heat sufficient for the most difficult vitrifications. After the operation, no glass was found in the crucible; but part of the alkali had been dissipated by the violence of the heat, and the diamond powder did not shew any signs of a beginning fusion. Thus we may confider it as an established truth, that the earths and stones called vitrifiable are not essentially and really so; that the fusibility of some of these, by which property they are rendered the fittest earths for vitrification, proceeds from heterogeneous matter with which they are mixed: and that, in general, the whitest, clearest, most transparent and hardest of these stones are also the most refractory and unfusible."

"[T]he purest and simplest of all earths ought to be also the heaviest; and accordingly... pure vitrifiable earth is... heavier than calcareous, argillaceous, gypseous, or other earths. ...[N]evertheless ...metals, metallic earths, and several kinds of spars, both calcareous and selenitic, are much heavier than the most compact vitrifiable stones ... [P]arts may be so arranged that void spaces may be left betwixt them, sometimes larger, and sometimes less, therefore a body composed of parts essentially lighter, may yet have a greater specific gravity than another body whose parts are essentially heavier; and this happens in all metals and metallic matters. ...Thus the gravity of metals and of metallic earths and stones ought not to prevent our considering the pure and elementary earthy principle as the heaviest of all natural substances."

"[W]e may consider the properties of elementary earth in the purest vitrifiable stones, and... compare them with the properties of the other elements. Since of these elements water is the most capable of our examination, we shall compare it with the purest vitrifiable earth; observing always, that we consider these elements in their state of aggregation; for we have no method by which their primary integrant parts can be known and considered separately."

"I do not believe that a pure verifiable earth, as a diamond, can be fused even in the focus of the best burning speculums: but supposing that a sufficient heat might be produced... it would then melt, and would even be reduced to vapors, if the heat were sufficiently violent; and when this heat should cease, it would, when it cooled, fix again, and become such a substance as it was before. The same would happen to vitrifiable earth in these circumstances, which does happen to water rendered fluid, and reduced to vapor by a certain heat, and which is again frozen into solid ice when that heat is removed. The differences, therefore, betwixt these two substances are only... in the degrees; but also these differences are very considerable."

"[A]n inference seems deducible, that the elements or the simplest substances which we know are essentially only one and the same matter, and only differ from each other in the quantity and in the form of their primary integrant molecules, which... have a greater or less tendency to unite together..."

"[W]e cannot doubt but that earth chiefly differs from the other elements by the powerful tendency which its parts have to each other, and by the force of their cohesion. For its hardness, fusibility, fixity, and even its gravity, are evidently the necessary consequences of this... the cause of the consistence of all solid bodies."

"Lastly, as without fire the whole world would be one mass of solid and immoveable matter, so without earth it would be a confused heap of fogs, vapors, a chaos of incoherent atoms, destitute of that harmony and equilibrium which sustain it."

"[T]he general tendency of the parts of matter to each other is the grand spring of the universe; that by this power, all combinations, solutions, and, in a word, all the movements and operations of nature are performed: and as... the earthy element possesses this tendency in the greatest degree, we ought to consider earth as being in this sense the most active and powerful of all elements. ...[T]he force with which they adhere together, and which renders them incapable of forming other unions, the extreme hardness, and the insolubility of a mass of pure earth, ought to demonstrate to a true philosopher, that if we suppose the parts of earth so separated ...that they cannot unite ...they must then possess all their force of tendency ...in a state of violent effort, and consequently must tend with extreme force to unite with any parts of matter ...within their reach ...[W]e know compounds in which the primitive integrant parts of the earthy element are only combined with the parts of water, which are incapable of satisfying all their tendency to union. These are the most simple saline substances, such as s and alkalis; and we may judge by the force and vehemence of the action of these solvents, how violent the action of the parts of earth would be, which should be capable of exerting all the attractive force which belongs to them."

"Although the entire mass of our globe be probably formed by an immense heap of elementary, vitrifiable, and even actually vitrified earth, as the illustrious Buffon believes, we do not find upon its surface but a very small quantity of this earth, unaltered, and in its primary state. Perhaps even none of it exists in that state: for, as we have observed, the common vitrifiable stones, which are chiefly formed of it, are very far from the degree of purity of primary elementary earth; and even perfect diamonds, which seem of all these stones to approach the nearest to this purity, seem to have been elaborated by the waters, if we can judge from their regularly crystallized form."

"We shall not be surprized at the scarcity of pure earthy element, if we consider that the surface of the earth... has been from the beginning of the world exposed to the constant action of the other elements; and that by uninterrupted operations, nature, assisted by fire, air, and water, has gradually disunited the integrant parts of elementary earth, and by combining them in manners and proportions infinitely various with parts of the other elements, has formed the numberless compound bodies, which occupy a certain thickness near the circumference of the globe, probably very small in comparison of the diameter of the earth, but very large with regard to us, whose greatest efforts only extend to a few hundred feet below its surface."

"[T]he earth which makes [shells and scales] of the crustaceous animals... takes the character of that earth which is called calcareous, and which is capable of conversion into quicklime by the action of fire. The earth which has entered into the composition of plants, and even of the bodies of animals, after having been deprived... of... principles of these compounds to which it was united, forms all the argillaceous earths. Some... partake both of the calcareous and of the argillaceous properties, and are called es. Marles have not yet been sufficiently well examined by chemists. They are either a mixture of clay and calcareous earth, or they have been so elaborated by nature as to be transformed into a particular earth, partly calcareous, and partly argillaceous, such as the earth of animal bones seems to be."

"As the earth which forms sands and the common impure vitrifiable stones retains more than the rest the essential properties of elementary earth, notwithstanding the heterogeneous, phlogistic, and other parts with which it is mixed; we cannot easily know whether it has once made a part of some very compound bodies, from the principles of which it has been more perfectly separated than the argillaceous and calcareous earths; or whether it be the primitive earth, which, without having made part of any intimate combination, has only been divided and conveyed by waters, and the parts of which have afterwards reunited, having only contracted a slight union with some phlogistic, metallic, and other matters, with which it is found mixed. This latter supposition appears to me to be the most probable. But very extensive researches in natural history and in chemistry are requisite to determined this question."

"[E]xcepting the purest vitrifiable earth, all the others are mixed with heterogeneous matter. By these remaining heterogeneous matters are the different kinds of earth specified and characterised: and as they all preserve and retain their peculiar character, we ought to conclude from thence, that these extraneous matters are very intimately united. To purify and simplify these mixed earths, so that they shall be assimilated to the purest vitrifiable earth, would be a fine problem. But, probably, this problem is beyond the power of our art. For... the perfect separation of two substances, united together, is exceedingly difficult, this difficulty must greatly increase, when one of the... substances... has a very strong attractive power, as earth has. This is the... reason why we find so small a portion of pure earth amongst the bodies within our reach; and that on the contrary, the globe is covered with so great a quantity of earthy substances differing from each other so much, that we might be inclined to believe them to be bodies essentially different."

"Earth (Animal) is the earth of shells of animals; or that which is obtained by , or putrefaction of animal substances. 1. The earths of the shells of Sea Fishes have the general properties of calcareous earths. It is said to differ from the mineral calcareous earths in being more difficultly soluble by vitriolic acid, and in being less disposed to vitrify along with salts and metallic glasses. The shells of eggs are also calcareous, but are somewhat fusible by fire. 2. The earths of calcined bones and horns are soluble by nitrous, marine, and vegetable acids, and with difficulty by vitriolic acid; but are not capable of being converted into quicklime by . They are said to be unfusible, even when mixed with salt, metallic glasses, and other fusible mixtures. They are therefore used in the composition of enamels and opake white glasses. Nevertheless, Wallerius affirms, that the earth of calcined bones, by intense heat, was changed, without addition, to a green glass. The same author says, that the earth of the whites and yolks of eggs was easily fusible, and that in general the fusibility of animal earths is in proportion to the softness of the parts from which they were obtained. 3. The earth of blood, flesh and skins of animals, is soluble by all acids, and is fusible by fire; that of blood and of other animal fluids being most fusible. This earth, like that of burnt bones and horns, is not calcareous; but both these kinds of earth are said to be rendered calcareous by being dissolved in acids, precipitated by fixed alkali from those acids, and afterwards calcined. They probably contain some mucilaginous substance, from which they cannot be entirely divested by fire without a previous solution in acids."

"The class of bodies called earths by chemists are nine in number; their names are Lime, Magnesia, Barytes, Strontites, Alumine or Argil, Silex, Yttria, Glucine and Zircone. The three last are recently discovered and scarce."

"The earths constitute the bases of the fossil kingdom. Though they have frequently been suspected to be compound bodies, and several attempts have been made to decompose them, it does not yet appear but that they are simple or elementary substances. Some of the earths possess alkaline properties; others are without such... but they all partake of the following characters: 1. They are incombustible, or do not unite with oxygen; 2. they are inferior to the metals in lustre and opacity; 3. they are sparingly soluble in water; 4. they are difficultly fusible, or resist great heat with out alteration; 5. they combine with acids; 6. they combine with each other, and with metallic oxides; and, 7. their specific gravities are from 1 to 5."

"The latest attempt to decompose the earths is that of Mr. Davy; he seems to have shewn, that some of the earths are analogous to the fixed alkalies, in respect to their properties of forming metals; but these metals, like those of the alkalies, are most probably compounds of hydrogen and the respective earths."

"Twenty years ago few substances seemed more likely to retain a permanent place in chemical arrangements, than the solid and refractory earths which compose the crust of the globe."

"Analysis has shewn, that the various stony or pulverulent masses which form our mountains, valleys, and plains, might be considered as resulting from combination or intermixture, in various numbers and proportions, of nine primitive earths, to which the following names were given:— 1. Baryta. 2. Strontia. 3. Lime. 4. Magnesia. 5. Alumina, or . 6. Silica. 7. Glucina. 8. Zirconia. 9. Yttria."

"Alkalis, s, metallic s, and s, were supposed to be of an entirely dissimilar constitution."

"The brilliant discovery by Sir H. Davy in 1808, of the metallic bases of , soda, strontia, and lime, subverted the ancient ideas regarding the earths, and taught us to regard them as all belonging, by most probable analogies, to the metallic class. According to an ingenious suggestion of Mr Smithson silica, however, ought to be ranked acids, since it has the power, in native mineral compounds, of neutralizing the alkaline earths, as well as the common metallic oxides. But as this property is also possessed by many metallic oxides, it can afford no evidence against the metallic nature of the siliceous basis. Alumina, by the experiments of Ehrman, may be made to saturate lime, producing a glass; and the triple compounds of magnesia, alumina, and lime, are perfectly neutral in . We might therefore refer alumina, as well as silica, to the same class with the oxides of , , , columbium, , , and . Alumina, however, bears to silica the same relation that oxide of antimony does to that of arsenic; the antecedent pair acting the part of bases, while the consequent pair act only as acids. The compound of the fluoric principle with silica is... mysterious... The almost universal function which silica enjoys, of saturating the alkaline oxides in the native earthy minerals, is exhibited in a very striking manner in Mr Allan's valuable Synoptic Tables. From his fifth to his fifteenth table of analyses, the column of silica is always complete, whatever deficiency or variation may occur in the columns of the earthy bases. At least, only a very few exceptions need be made for the oriental gems, which consist of strongly aggregated alumina."

"Whatever may be the revolutions of chemical nomenclature, mankind will never cease to consider as Earths those solid bodies, composing the mineral strata, which are incombustible, colourless, not convertible into metals by all the ordinary methods of reduction, or, when reduced by scientific refinements, possessing but an evanescent metallic existence, and which either alone, or at least when combined with , are insipid and insoluble in water."

"Substances which resembled salts in general appearance, but were insoluble in water, and very fixed in the fire, were called "earths"; and, as was generally done in those days, the existence of a primordial earth was assumed, more or less of which was supposed to be present in actual earths. This recognition of the possibility of more or less of the primordial earth being present in actually occurring earths, of course necessitated the existence of various kinds of earth. The earths were gradually distinguished from each other; lime was recognized as a substance distinct from baryta, baryta as distinct from alumina, etc."

"Stahl taught that one essential property of an earth was by fire, with production of a substance more or less like glass. This property was possessed in a remarkable degree by quartz or silica. Hence silica was regarded as the typical earth, until Berzelius, in 1815, proved it to be an acid. But the earths resembled alkalis, inasmuch as they too combined with, and so neutralized, ."

"There is an alkali hidden in every earth, said some chemists. An alkali is an earth refined by the presence of acid and combustible matter, said others."

"Earths thus came to be included in the term "alkali," when that term was used in its widest acceptation. But a little later it was found that some of the earths were thrown down in the solid form from their solutions in s by the addition of alkalis; this led to a threefold division... The distinction at first drawn between "earth" and "alkali" was too absolute; the intermediate group of "alkaline earths" served to bridge over the gap between the extreme groups."

"At this stage of advance, then, an earth is regarded as differing from an alkali in being insoluble, or nearly insoluble in water; in not being soapy to the touch, and not turning vegetable reds to blue: but as resembling an alkali, in that it combines with and neutralizes an acid; and the product of this neutralization, whether accomplished by an alkali or by an earth, is called a salt."

"To the earth or alkali, as being the foundation on which the salt is built, by the addition of acid, the name of base was given by Rouelle in 1744."

"But running through every conception which was formed of these substances-acid, alkali, earth, salt-We find a tendency, sometimes forcibly marked, sometimes feebly indicated, but always present, to consider salt as a term of much wider acceptation... An acid and an alkali, or an acid and an earth, combine to form a salt; but the salt could not have been thus produced unless the acid, the alkali and the earth had contained in themselves some properties which, when combined, form the properties of the salt."

"The acid, the alkali, the earth, each is, in a sense, a salt. The perfect salt is produced by the coalescence of the saltness of the acid with the saltness of the alkali. This conception finds full utterance in the names, once in common use, of sal acidum for acid, sal alkali for alkali, and sal salsum or sal neutrum for salt. All are salts; at one extreme comes that salt which is marked by properties called acid properties, at the other extreme comes the salt distinguished by alkaline properties, and between these, and formed by the union of these, comes the middle or neutral salt."

"It is thus that the nomenclature of chemistry marks the advances made in the science. "What's in a name?" To the historical student of science, almost everything."

"Hari Seldon devised psychohistory by modeling it upon the kinetic theory of gases. Each atom or molecule in a gas moves randomly so that we can't know the position or velocity of any one of them. Nevertheless, using statistics, we can work out the rules governing their overall behavior with great precision. In the same way, Seldon intended to work out the overall behavior of human societies even though the solutions would not apply to the behavior of the individual human beings."

"In this book I have tried... to make clearly comprehensible the path-breaking works of Clausius and Maxwell. The reader may not think badly of me for finding also a place for my own contributions. These were cited respectfully in Kirchhoff's lectures [on Maxwell's kinetic theory] and in Poincare’s Thermodynamique at the end, but were not utilized where they would have been relevant. From this I concluded that a brief presentation, as easily understood as possible, of some of the principal results of my efforts might not be superfluous. Of great influence on the content and presentation was what I have learned at the unforgettable meeting of the British Association in Oxford and the subsequent letters of numerous English scientists, some private and some published in Nature. I intend to follow Part I by a second part, where I will treat the van der Waals theory, gases with polyatomic molecules, and dissociation. ...Unfortunately it was often impossible to avoid the use of long formulas to express complicated trains of thought, and... to many who do not read over the whole work, the results will perhaps not seem to justify the effort expended. Aside from many results of pure mathematics which, though likewise apparently fruitless at first, later become useful in practical science as soon as our mental horizon has been broadened, even the complicated formulas of Maxwell’s theory of electromagnetism were often considered useless before Hertz’s experiments. I hope this will not also be the general opinion concerning gas theory!"

"Boltzmann decided to publish his lectures, in which the most important parts of the theory, including his ...contributions, were carefully explained. ...[H]e included his mature reflections and speculations on such questions as the nature of irreversibility and the justification for using statistical methods in physics. His Vorlesungen über Gastheorie was... the standard reference... for advanced researchers, ...[and] a popular textbook ...for the first quarter of the [20th] century ...The reason why the classical theory works is that, while the internal structure of molecules must be described by quantum mechanics, the interaction between two molecules can be fairly well described by a classical model which ignores this structure and simply uses a postulated force law whose parameters can be chosen to fit experimental data. ...Aside from phenomena at very high densities or very low temperatures, the only property that the classical theory fails to account for is the ratio of specific heats. ...Boltzmann ...simply concludes that for some unknown reason all the possible internal motions of a molecule do not have an equal share in the total energy, and takes this into account as an empirical fact."

"Boyle... proposed a theoretical explanation for the elasticity of air... "a heap of little bodies, lying upon one another"... The atoms are said to behave like springs... Boyle also tried the "crucial experiment" which was to help overthrow his own theory in favor of the kinetic theory two centuries later, though he did not realize its significance... Experiment No. 26... places a pendulum in the evacuated chamber... [A]bsence of air makes hardly any difference to the period of the swings or the time... to come to rest. In 1859, James Clerk Maxwell deduced from the kinetic theory that the viscosity of a gas should be independent of its density... which would be very hard to explain on the basis of Boyle's theory. ...Neither Boyle nor Newton claimed that the hypothesis of repulsive forces between atoms is the only correct explanation for gas pressure; both were willing to leave the question open. Boyle mentions the Descartes theory of vortices (1644)... somewhat closer in spirit to the kinetic theory since it relies more heavily on the rapid motion of the parts of the atom as a cause of repulsion. (Though Descartes did not believe in "atoms" in the classical sense.) Nevertheless, the Boyle-Newton theory of gases was apparently accepted by most scientists until about the middle of the 19th century, when the kinetic theory finally managed to overcome Newton's authority."

"It is difficult to understand the relative lack of progress in gas theory during the 18th century ...[T]here was little interest in the properties of freely moving atoms. The atoms in gas were... conceived as... suspended in the ether, although they could vibrate or rotate enough to keep other atoms from coming too close. This model was... awkward... mathematically, as... seen from an... attempt by Leonhard Euler in 1727. ...[O]ne contribution from this period has been... recognized as the first kinetic theory of gases. This is Daniel Bernoulli's derivation of the gas laws from a "billiard ball" model—in 1738... [H]is kinetic theory is... a small part of a treatise [Hydrodynamica (1738)] on hydrodynamics... Bernoulli's formulation and... applications of the principle of conservation of mechanical energy (...' ..."living force" ...) were ...more important than the fact that he proposed a kinetic theory ...a century ahead of its time ...Heat was still regarded as a substance ...Bernoulli's assumption that heat was nothing but atomic motion was unacceptable, especially to scientists interested in... radiant heat. The assumption that atoms could move freely through space until they collided like billiard balls... neglected the drag of the ether and oversimplified the interaction between atoms. ...When physics reached the stage of development at which the kinetic theory no longer conflicted with established principles, ...[it] had almost been forgotten and had to be rediscovered. ...In a very real sense, the man who persuades the world to adopt a new idea has accomplished as much as the man who conceived that idea."

"The influence of Quetelet's ideas spread throughout the sciences, even to the physical sciences. The two primary founders of the modern kinetic theory of gases, based on considerations of probability, were James Clerk Maxwell and Ludwig Boltzmann. Both acknowledged their debt to Quetelet. ...[H]istorians generally consider the influence of the natural sciences on the social sciences, whereas in the case of Maxwell and Boltzmann, there is an influence of the social sciences on the natural sciences, as Theodore Porter has shown."

"It will be shown in this paper that, according to the molecular-kinetic theory of heat, bodies of microscopically visible size suspended in liquids must, as a result of thermal molecular motions, perform motions of such magnitude that these motions can easily be detected by a microscope. It is possible that the motions to be discussed here are identical with the so-called "Brownian molecular motion"; however, the data available to me on the latter are so imprecise that I could not form a definite opinion on this matter. If it is really possible to observe the motion to be discussed here, along with the laws it is expected to obey, then classical thermodynamics can no longer be viewed as strictly valid even for microscopically distinguishable spaces, and an exact determination of the real size of atoms becomes possible. Conversely, if the prediction of this motion were to be proved wrong, this fact would provide a weighty argument against the molecular-kinetic conception of heat."

"In 1909 Perrin suspended particles of in a liquid of slightly lower density, and found that the heavy particles did not sink to the bottom of the lighter liquid; they were prevented from doing so by their own Brownian movements. If the liquid had been infinitely fine-grained, with molecules of infinitesimal size and weight, every solid particle would have had as many impacts from above as below; these impacts, coming in a continuous stream, would have just cancelled one another out, so that each particle would have been free to fall to the bottom under its own weight. But when they were bombarded by molecules of finite size and weight, the solid particles were hit, now in one direction and now in another, and so could not lie inertly on the bottom of the vessel. From the extent to which they failed to do this, Perrin was able to form an estimate of the weights of the molecules of the liquid... and this agreed so well with other estimates that there could be but little doubt felt as to the truth either of the kinetic theory of liquids, or of the associated explanation of the Brownian movements."

"Now, although the plans of the edifice of the electromagnetic theory of light were laid in 1880 by H. A. Lorentz, and even indicated much earlier by W. Weber, a full 10 years were required before the discoveries of Heinrich Hertz gave the impetus to collect the building stones and work them into shape. In the years 1890-93 a number of works appeared by F. Richarz, H. Ebert and G. Johnstone Stoney, mostly dealing with the mechanism of the emission of luminous vapours, and in which attempts are made, on the basis of the kinetic theory of gases, to determine the magnitude of the elementary electrical quantity, called by Stoney by the now universally accepted name of electron. ...H. Ebert proved that the amplitude of an electron in luminous sodium vapour need only be a small fraction of a molecular diameter in order to excite a radiation of the absolute intensity determined by E. Wiedemann. The way of determining the amount of electricity contained in the electron is very simple. The quantity of electricity required for the electrolytic evolution of 1 cubic cm. of any monatomic gas is divided by Loschmidt's number—i.e., the number of gas molecules contained in 1 cubic cm."

"One of the most important and interesting aims of is to explain the properties of matter in terms of the motions and spatial arrangements of atoms and molecules. This aim has been more nearly achieved in the physical chemical study of gases at low pressures [below a few atmospheres at ordinary temperatures] than the study of matter in any other conditions. ... The structure of gases at these pressures is particularly simple: such gases are collections of molecules which move randomly in space and which collide with each other relatively infrequently—that is, the molecules are so far apart that much of the time they exert little influence on each other. ...[T]he properties of the gaseous state play a role in many important practical processes, such as [in]... the internal combustion engine, the function of the lungs, the motions of the winds across the earth and the flight of airplanes. Gases... provide a useful and pedagogically attractive starting point for the introduction of students to physical chemistry."

"The kinetic theory of gases is a small branch of physics which has passed from the stage of excitement and novelty into staid maturity. ...Formerly it was hoped that the subject of gases would ultimately merge into a general kinetic theory of matter; but the theory of condensed phases... today, involves an elaborate and technical use of wave mechanics, and for this reason it is best treated as a subject in itself. The scope of the present book is, therefore, the traditional kinetic theory of gases. ...[A]n account has been included of the wave-mechanical theory, and especially of the degenerate Fermi-Dirac case... There is also a concise chapter on , which... may be of use as an introduction... [T]he discussion of electrical phenomena has been abbreviated... the latter voluminous subject is best treated separately. ...[F]undamental parts have been explained... [as] to be within the reach of college juniors and seniors. The... wave mechanics and statistical mechanics... are of graduate grade. ...[A] number of carefully worded theorems have been inserted in the guise of problems, without proof... to give... a chance to apply... lines of attack exemplified in the text. To facilitate use as a reference book, definitions have been repeated freely, I hope not ad nauseam. ...Ideas have been drawn freely from ...books such as ...of Jeans and Loeb..."

"The last thirty years have seen the beginning and development of a new period in physics and chemistry, namely the atomic period. In contrast to the period preceding it where nature's processes were described in terms of continua, recent developments have emphasized the discrete structure of the submicroscopic universe. Thus, today one hears of the atoms of matter, the atoms of electricity, and even the atoms of energy, the quanta. ...[T]he atomic theory of matter is the oldest and perhaps the most complete. ...[B]ecause of its relative simplicity the problem of the atomic theory of gases, in the form of the kinetic theory of gases, has attained the highest degree of perfection in this field. Its admirable methods of analysis are therefore indispensable... This book... endeavors to develop the various concepts... independently...Besides a simple introduction of each concept it gives derivations... elementary ones, using little or no calculus; more advanced classical derivations; and in some cases the most recent developments available. It also contains the comparison of the theoretical deductions with modern experiment and a critique of the theories."

"The science of Thermodynamics, founded by the labors of these three illustrious men [Nicolas Léonard Sadi Carnot, William Thomson & Rudolf Clausius], has led to the most important developments in all departments of physical science. It has pointed out relations among the properties of bodies which could scarcely have been anticipated in any other way; it has laid the foundation for the Science of Chemical Physics; and, taken in connection with the , as developed by Maxwell and Boltzmann, it has furnished a general view of the operations of the universe which is far in advance of any that could have been reached by purely dynamical reasoning."

"The first edition of this book appeared in 1877, at the time of the most rapid and beautiful development of the kinetic theory of gases. About twenty years before, the founders... Kronig and Clausius, had explained the expansive tendency of gases, and had calculated their pressure on the assumption that the smallest particles of gases do not repel each other, but are in rapid motion. From the theory based on this supposition not only were the laws of gases... deduced... but also new laws, hitherto undreamt of, were discovered... [and] afterwards confirmed... by experiment. These results, which we owe to Maxwell and Clausius, quickly won to the theory many friends and adherents. ...I undertook ...to exhibit the ...theory ...such ...as to be more easily intelligible ...especially to chemists and other natural philosophers to whom mathematics are not congenial. ...I endeavoured ...not only to develop the theory by calculation, but ...to support it by observation and found it on experiment. I... collected... and summarised, the observations by which the admissibility of the theory might be tested and its correctness proved. ...The mathematical discussions form ...an Appendix which ...need not be studied by every reader ..."

"The researches of Galileo, followed up by Huygens and others, led to those modern conceptions of Force and Law, which have revolutionized the intellectual world. The great attention given to mechanics in the seventeenth century soon so emphasized these conceptions as to give rise to the Mechanical Philosophy, a doctrine that all the phenomena of the physical universe are to be explained upon mechanical principles. Newton's great discovery imparted a new impetus to this tendency. The old notion that heat consists in an agitation of corpuscles was now applied as an explanation to the chief properties of gases. The first suggestion in this direction was that the pressure of gases is explained by the battering of the particles against the walls of the containing vessel, which explained Boyle's law of the compressibility of air. Later, the expansion of gases, Avogadro's chemical law, the diffusion and viscosity of gases, and the action of Crooke's radiometer were shown to be consequences of the same kinetical theory; but other phenomena, such as the ratio of the specific heat at constant volume to that at constant pressure, require additional hypotheses, which we have little reason to suppose are simple, so that we find ourselves quite afloat. In like manner with regard to light..."

"The first constant... is connected with the definition of temperature. If temperature were defined as the mean of a molecule in a , which is a minute energy indeed, this constant would have the value ⅔. But in the conventional scale of temperature the constant ...[instead] assumes an extremely small value... intimately connected with the energy of a single molecule... [I]ts accurate determination would lead to the calculation of the mass of a molecule and... associated magnitudes. This constant is frequently termed Boltzmann's constant, although to the best of my knowledge Boltzmann... never introduced it (...he, as appears from... his statements, never believed it would be possible to determine this constant accurately)..."

"If we study the history of science we see happen two inverse phenomena, so to speak. Sometimes simplicity hides under complex appearances; sometimes it is the simplicity which is apparent, and which disguises extremely complicated realities. ...What is more complicated than the confused movements of the planets? What simpler than Newton's law? ...In the kinetic theory of gases, one deals with molecules moving with great velocities, whose paths, altered by incessant collisions, have the most capricious forms... The observable result is Mariotte's simple law. ...The law of great numbers has reestablished simplicity in the average. ...No doubt, if our means of investigation should become more and more penetrating, we should discover the simple under the complex, then the complex under the simple, then again the simple under the complex, and so on, without our being able to foresee what will be the last term. We must stop somewhere, and that science may be possible, we must stop when we have found simplicity. This is the only ground on which we can rear the edifice of our generalizations."

"The old mechanical and atomic hypotheses have, during recent years, become so plausible that they have ceased to seem like hypotheses; atoms are no longer just a convenient fiction. It seems almost as if we could see them, now that we know how to count them. ...The kinetic theory of gases has thus received unexpected corroboration. ...The remarkable counting of the number of atoms by Perrin completed the triumph of the atomic theory. ...In the processes used with the Brownian phenomenon, or in those used for the law of radiation, we do not deal directly with the number of atoms, but with their degrees of freedom of movement. In that process where we consider the blue of the sky, the mechanical properties of the atoms come into play; the atoms are looked upon as producing an optical discontinuity. ...The atom of the chemist is now a reality. But that does not mean that we have reached the ultimate limit of the divisibility of matter. When Democritus invented the atom he considered it as the absolutely indivisible element within which there would be nothing further to distinguish. That is what the word meant in Greek. ... the atom of the chemist would not have satisfied him since that is not indivisible; it is not a true element; it is not free from mystery, from secrets. The chemist's atom is a universe. Democritus would have considered, even after so much trouble in finding it, that we were still only at the beginning of our search—these philosophers are never satisfied. ...This atom disintegrates into yet smaller atoms. What we call is the perpetual breaking up of atoms. ...Each atom is like a sort of solar system where the small negative electrons play the role of planets revolving around the great... sun. ...the atom of a radioactive body is a universe within itself and a world subject to chance."

"The idea of a Kinetic Theory of Gases originated with J. Bernouilli about the middle of the last century, but the first establishment of the theory on a scientific basis is due to Professor Clausius. During the last few years the theory has been greatly developed by many physicists, especially by Professor Clerk Maxwell in England and Professor Clausius and Dr. Ludwig Boltzmann... and although still beset by formidable difficulties, it has succeeded in explaining most of the established laws of gases in so remarkable a manner as to render it well worthy of the attentive consideration of scientific men. ...For the most part I have followed the method of treatment adopted by Dr. Ludwig Boltzmann in some very interesting memoirs ..."

"Mifepristone may be the least marketed pharmaceutical product in the U.S. There aren’t any ads for it on TV. Most doctors can’t prescribe it. Pharmacists don’t know much about it, since it doesn’t sit on the shelves at CVS or Walgreens. It would be reasonable to assume this is all because mifepristone is exceptionally dangerous. But it sends fewer people to the ER than Tylenol or Viagra."

"There are several ways of performing Tas'id, (a rising up) in the (the sublimatory apparatus), and the substances which the chemists sublime in it are Mercury, Arsenic sulfide, Sulfur and Sal-Amoniac. They are placed after treatment in the aludel, and the cover being fitted in position over it, a fire is lit. Then the substance rises up, and settles on the shelf..."

"The natural principles in the mines are mercury and sulphur. All metals and minerals whereof there be sundry and diverse kinds are begotten of these two. But I must tell you that nature always intendeth and striveth to the perfection of gold. But many accidents coming between change the metals, for according to the purity and impurity of the two afore said principles, mercury and sulphur, pure and impure metals are engendered. Sulphur is not the last amongst the principles because it is a part of the metal. Yea, and the principle part of the philosopher's stone, and many wise men have left in writing diverse and very true things of sulphur. For the blood of sulphur is that inward virtue and dryness which congeals quicksilver into gold, and imparts health and perfection in all bodies."

"If you prudently desire to make our elixir, you must extract it from a mineral root. For as Geber saith, you must obtain the perfection of the matter from the seeds thereof. Sulphur and mercury are the mineral roots, and natural principles, upon which nature herself acts and works in the mines and caverns of the earth, which are viscous water, and subtil spirits running through the pores, veins, and bowels of the mountains. Of them is produced a vapour or cloud, which is the substance and body of metals united, ascending, and reverberating upon its own proper earth, (as Geber sheweth) even till by a temperate digestion through the space of a thousand years, the matter is fixed, and converted into a mineral stone, of which metals are made."

"Volcanic ash, despite the name, is dense as rock and can cause significant damage to structures, power lines and communications. It is also toxic because it contains chemicals such as sulfur, chlorine or fluorine, and it can therefore affect water supplies."

"There is another type of exploding supernova that also seeds the Galaxy with elements. This is the . This explosion involves a binary system in which a star and an intermediate-mass star (a ) orbit each other. The two stars are so close to each other that the white dwarf gradually pulls a considerable amount of material from the outer envelope of the expanding red giant. At a certain point the white dwarf will acquire so much mass that it collapses under its own weight and produces an explosion that blasts the bulk of its material into the interstellar medium—mostly in the form of iron, but also some sulfur, and . Such explosions contributed about 70 percent of the iron we see today in the Galaxy."

"'isn't it brimstone morning?' 'I forgot, my dear,' rejoined Squeers; 'yes, it certainly is. We purify the boys' bloods now and then, Nickleby.' 'Purify fiddlesticks' ends,' said his lady. 'Don't think, young man, that we go to the expense of flower of brimstone and molasses, just to purify them; because if you think we carry on the business in that way, you'll find yourself mistaken, and so I tell you plainly. ...They have the brimstone and treacle, partly because if they hadn't something or other in the way of medicine they'd be always ailing and giving a world of trouble, and partly because it spoils their appetites and comes cheaper than breakfast and dinner. So, it does them good and us good at the same time, and that's fair enough I'm sure.'"

"Proposals for chemical weapons that arose during the American Civil War are described. Most incendiary and all biological agents are excluded. The described proposals appeared primarily in periodicals or letters to government officials on both sides. The weapons were usually meant to temporarily disable enemy combatants, but some might have been lethal, and Civil War caregivers were ill-prepared to deal with the weapons’ effects. Evidently, none of the proposed weapons were used. In only one instance was use against civilians mentioned. Among the agents most commonly proposed were cayenne pepper or other plant-based irritants such as black pepper, snuff, mustard, and veratria. Other suggested agents included chloroform, chlorine, hydrogen cyanide, arsenic compounds, sulfur, and acids. Proponents usually suggested that the chemicals be included in explosive artillery projectiles. Less commonly proposed vehicles of delivery included fire engines, kites, and manned balloons. Some of the proposed weapons have modern counterparts."

"From this theoretical structure of nature evolved the assumptions upon which alchemy was based: the unity of the universe and relatedness of all natural phenomena as expressed by the idea of from which all bodies were formed and into which they might again be dissolved, and the existence of a potent transmuting agent capable of promoting the change of one kind of material into another... This transmuting agent became known as the philosopher's stone, an object so quintessential it could not only transmute metals, but cure illness and prolong life....The process was composed of three stages. In the first, the alchemist heated the primary material, usually a blend of salt, mercury and sulfur, until it dissolved and turned black with decay. Under this continuous heat the liquid became dry, powdery and white. If all was done properly, the materials would eventually recombine and become a brilliant red, the color of the philosopher's stone."

"...let us rather choose Arm'd with Hell flames and fury all at once O're Heav'ns high Towrs to force resistless way, Turning our Tortures into horrid Arms Against the Torturer; when to meet the noise Of his Almighty Engin he shall hear Infernal Thunder, and for Lightning see Black fire and horror shot with equal rage Among his Angels; and his Throne it self Mixt with Tartarean Sulphur, and strange fire, His own invented Torments."

"The crude sulphur found in Sicily and other places is heated in pots, whereupon the sulphur melts and floats on the surface of the earthy matter which remains at the bottoms of the pots; the melted sulphur is poured into moulds, where it solidifies, and the earthy matter left in the pots is thrown away."

"In some parts of the East, sulphur is separated from the earthy matter wherewith it is mixed in the soil, by heating the crude material very strongly in earthen pots, each covered with another similar pot inverted on it. The sulphur melts and then becomes gaseous and the gaseous, sulphur condenses in the upper pots, which are comparatively cool; the fine yellow powder which condenses is approximately pure sulphur; the earthy impurities remain in the lower pots."

"Recent "clean coal technologies" and use of low sulfur fuels have resulted in decreasing sulfate concentrations..."

"Putting a low price on valuable environmental resources is a phenomenon that pervades modern society. Agricultural water is not scarce in California; it is underpriced. Flights are stacked up on runways because takeoffs and landings are underpriced. People wait for hours in traffic jams because road use is unpriced. People die premature deaths from small sulfur particles in the air because air pollution is underpriced. And the most perilous of all environmental problems, climate change, is taking place because virtually every country puts a price of zero on carbon dioxide emissions."

"Mineral bodies are vapors which have coagulated in nature in the course of long lapses of time, and the first things which coagulate are quicksilver and sulphur, for these and not water or oil (oleum) are the elements of minerals, for the first... (quicksilver) is generated from a water and the other (sulphur) from an oil. Upon these things there operates a gentle digestion constantly with heat and moisture until they are solidified and from them (metallic) bodies are generated by gradual mutation in thousands of years. For if they remain in their minerals, nature purifies them until they arrive at a kind of gold or silver. But by the subtlety of the artist, transmutation of this kind is made in one day or in a brief space of time."

"There are seven things that can be elongated by hammering at the furnace, namely Sol, that is gold, luna (silver), tin, copper (aes), iron, lead. These are formed in nature under the earth. Gold is generated in the earth by the great heat of the sun from excellent quicksilver and red and pure sulphur by digestion in the rocks for a hundred years or more; silver from pure quicksilver and pure sulphur digested for a hundred years. But copper (...cuprum instead of aes) from impure quicksilver and impure sulphur digested for a hundred years. ...Lead, the philosophers say, is made under the earth from impure and thick quicksilver and from the worst sulphur and is a crude mixture and not well digested. And lead... renders gold breakable... Tin, however, is made from excellent and pure quicksilver, but from the poorest sulphur impure and not well digested. Iron is from thick quicksilver and thick red sulphur, and is not sufficiently digested."

"Now, according to the ancient Sages there are two principles of things, and more particularly of metals, namely, Sulphur and Mercury; according to the Moderns there are three: Salt, Sulphur, and Mercury, and the source of these principles are the elements; of which it therefore behoves us to speak first. Be it known to the students of this art that there are four elements, and that each has at its centre another element which makes it what it is. These are the four pillars of the world. They were in the beginning evolved and moulded out of chaos by the hand of the Creator; and it is their contrary action which keeps up the harmony and equilibrium of the mundane machinery; it is they which, through the virtue of celestial influences, produce all things above and beneath the earth."

"He can perform a thousand things, and is the heart of all. He can perfect metals and minerals, impart understanding to animals, produce flowers in herbs and trees, corrupt and perfect air; in short, he produces all the odours and paints all the colors of the world. ...Know friend, that sulphur is the virtue of the world. And though Nature's second-born, yet the oldest of all things. To those who know him, however, he is as obedient as a little child. He is most easily recognized by the vital spirit in animals, the colour in metals, the odour in plants. Without his help his mother can do nothing."

"Whip me, ye devils, From the possession of this heavenly sight! Blow me about in winds! Roast me in sulphur! Wash me in steepdown gulfs of liquid fire! O Desdemon! dead, Desdemon! dead! O! O! O!"

"Of Sulphur, Pliny states, there are four kinds, but he makes no very intelligible characterization of their differences. "Live" sulphur (sulphur vivum), ocurring in masses or blocks is the only kind used in medicine. The others are used respectively by fullers, for the fumigation of wool, and the preparation of lamp wicks (...evidently ...as we use it in matches). Sulphur was also used in religious ceremonies, and for fumigating houses, and for fumigating (bleaching) cloth. The virtues of sulphur are to be perceived in certain hot mineral springs, and there is no substance that ignites more readily, "a proof that there is in it a great affinity for fire.""

"On November first, 1772, Lavoisier had deposited a sealed note with the Secretary of the Academy of Sciences, in which he states that he has discovered the sulphur and when burned gained weight. "This increase of weight is due to a great quantity of air which becomes fixed during the combustion and which combines with the vapours." He expresses his conviction that the same is true of all combustions and s."

"His alchemical doctrine, that everything consisted of three elements—mercury, sulphur, and salt—is adapted from old authors, but he was the first to use the word "alcahest" to indicate the universal menstruum or , which at that time was a special object of research. He describes this liquor, alcahest, as having great power over the , comforting and confirming it, and preserving it from dropsy and other diseases that take their origin within it. ...Unhappily, he does not give precise directions for the preparation of this invaluable remedy."

"He arranged the several parts of man, his own universal elements, and the Aristotelian elements in triplets, thus :—"

"(1523-83)... adopted the reasoning of scholastic philosophy and thus weakened the force of his attack, but he pointed out many contradictions in the writings of Paracelsus and his followers, denied the existence of the philosopher's stone, and combated the idea that mercury, sulphur, and salt are the elements of living bodies."

"After a visit to Germany, France, England, and the Scottish lead mines, Thurneysser started mining and sulphur-extracting in 1558..."

"[T]he writings and labours of the alchemists were both extensive and important. ...[T]heir studies, although misdirected, were not... haphazard. The alchemists had a definite, and... logical, system of philosophy... [T]hey recognised—(1) the unity of matter; (2) the three principles—philosophical mercury, sulphur, and salt; (3) the four elements—fire, air, water, and earth; and (4) the seven metals—gold, silver, mercury, copper, , tin, and ."

"All metals and minerals consist of certain principles. These were at first called "mercury" and "sulphur," not the ordinary substances... but a philosophical mercury and a philosophical sulphur."

"Traces of these ancient conceptions are still to be recognised in the word "quick-silver," that is living silver, a literal translation of argentum vivum. A term "quick-sulphur" (sulphur vivum) was also in use, but it has long since disappeared."

"The mercury of a metal... represented its lustre, volatility, fusibility, and malleability; the sulphur of the metal, its colour, combustibility, affinity, and hardness."

"The salt of the was merely a means of union between the mercury and the sulphur, just as the vital spirit in man unites soul and body. It was doubtless devised to impart a triple form to the idea, in conformity with the method of the theological schoolmen."

"Mercury, sulphur, and salt were not three matters, but one, derived from the '."

"[W]hen an alchemist converted a metal into its oxide, or, as they expressed it, "made a " of it, he thought he had volatilised its mercury and fixed its sulphur. When he distilled ordinary mercury and found a solid residue in the , he called it the "sulphur" of mercury; when he found a sublimed product in the receiver (mercury bichloride), he termed it the "mercury" of mercury or "corrosive sublimate.""

"The more logical mind of Artephius Longaevus introduced a modification of this theory. He distinguished two properties in a metal—the visible and the occult. The former, comprehending its colour, lustre, extension, and other properties visible to the eye, he called its "sulphur"; the latter, comprehending its fusibility, malleability, volatility, and other properties not visible until after... special treatment, he called its "mercury.""

"They were thus able to apply the conception of the three principles to that of the four elements. Earth corresponded to philosophical sulphur, and water to philosophical mercury. Later, when they conceived philosophical salt, they devised a fifth element called "quintessence" or "ether." which corresponded to the third principle. Thus, if an alchemist distilled wood and obtained an inflammable gas, a liquid oil and a solid residue, he said that he had decomposed the wood into its elements—fire, water, and earth."

"The sulphur of a metal was its active principle; the mercury its passive; the salt was the link which united the other two."

"The sulphur, the property of dryness and heat, ultimately overcame the mercury, the property of wetness and cold, and thus changes were effected. ...[S]ulphur was the father, mercury the mother, and metals were conceived between them. In this expression the philosophical principles are meant, not the ordinary substances called sulphur and mercury."

"[A]lchemists accounted for the diversity of metals by five causes:— 1. Variation in the proportion of the principles, mercury and sulphur. 2. Variation in the purity of these principles. 3. Variation in the duration of the period of concoction to which the compound was subjected in the bowels of the earth. 4. Variation in planetary influences. 5. Variation in accidental influences."

"At a still later date it was argued that exact and natural sciences proceed by induction and deduction, and occult and spiritual sciences by analogy. Following out this line of thought the alchemists produced the following remarkable :—"

"These mystic alchemists interpreted the three principles in their own fashion. Mercury, the passive and female principle, was matter; sulphur, the active and male principle, was force; and salt, the middle term in the proposition, was movement, which applied force to matter. Or, expressed in another shape, mercury was the subject: sulphur, the cause; and salt, the effect. Symbolically, the theory was represented by an equilateral triangle, in one angle of which was the sign of sulphur or force; in the second, the sign of mercury or matter; and in the third, the sign of salt or movement."

"He asserted that the metals are composed of the mercury and sulphur of the philosophers, to which he added philosophical salt. The philosopher's stone, he said, is composed of the same materials."

"He strongly maintained the virtues of aurum potabile (liquid gold), and wrote a book entitled Medicinae Chymicae et Veri Potabilis Auri Assertio (1610). Another tract, De Lapide philosophorum et Lapide Rebis, related to the older alchemy. ...[I]n alchemical symbolism "Rebis" was the name given to the hermaphrodite figure representing the union of the great philosophical principles, sulphur and mercury, in the operation of making the philosopher's stone..."

"He observed that the fumes of sulphur blacken ; he purified by means of arsenic and ; he made artificial rubies and other precious stones by tinting glass with metallic oxides; he described fluor spar as a flux for metals and their oxides; he oxidised sulphur with ; he knew that alcohol is obtained by distilling the fermented juice of sweet fruits; he proved that the acid extracted from and from ferrous sulphate (green vitriol) is the same as that obtained by burning sulphur with saltpetre, that is to say, it is sulphuric acid; and he discovered tin tetrachloride (stannic chloride), which is sometimes called Liquor fumans Libavii. It is a truly remarkable record of practical work, considering the age in which Libavius lived."

"Paracelsus had discarded the disgusting decoctions of Galen and introduced chemical medicines, while Libavius and Sala had dismissed the fanatical conceptions which disfigured and almost nullified the teachings of both Paracelsians and Rosicrucians, but chemists still adhered either to the Aristotelian doctrine of the four elements, or to the later theory of the three principles (mercury, sulphur, and salt). (1577—1644) was the first to deny these propositions, and to begin a revolution in the philosophy of chemistry."

"Sulphuric acid he made by distilling green vitriol (ferrous sulphate), and by distilling nitre (potassium nitrate), and (double sulphate of potassium and aluminium). he prepared, but said it was of little use as a medicine."

"In 1648 he demonstrated the possibility of making blue vitriol () by boiling copper with sulphuric acid."

"[T]he most valuable work of Cavendish was contained in the two papers "Experiments on Air" (1784-5)... to determine the phlogistication of air... [i.e.,] the change in air when s are calcined in contact with it, and when sulphur, , or similar substances, are burned in it."

"He noticed that when copper and sulphur are mixed, they exhibit an , which increases with increasing temperature until finally they combine, and all traces of electricity disappear. Hence, he inferred that the same forces which, acting on masses at a distance, produce electric phenomena, when acting on atoms at small distances, produce chemical combination, the positive electricity of the one atom attracting and holding the negative of the other. In the positive charge is on one and the negative on the other, but these two charges have to be discharged through the electrode before the elements are set free. This is the reverse of what takes place in combination. Davy in this view differed from the electro-chemical theory of Berzelius."

"By 3000 BCE the Sumerians, perhaps while heating copper to make it more malleable, had discovered that more copper could be retrieved from the fire if the metal were heated with certain types of dirt and stones—that is, certain earths. These earths were the metal s, and the process they discovered, ', reduced metal salts to pure metal by the action of in the fire. The process of changing metal salts into pure metal is known as reduction because the metal without the accompanying oxygen, , or sulfur of the salt weighs less than the ore. Eventually metal workers learned to distinguish various metal-bearing ores by color, texture, weight, flame color, or smell when heated (such as garlic odor of ores) and they could produce a desired material on demand."

"The did not arrive in China until around 1500 BCE, and iron appeared only about 500 BCE, but by the beginning of their alchemical age, around 100 CE, the Chinese had knowledge of and ... mercury, sulfur and several of the common salts, such as ."

"Pliny recorded processes involving metals, salts, sulfur, glass, mortar, soot, ash, and a large variety of s, earths, and stones."

"[C]hemical weapons were not new to the world. Besieged towns had thrown pots of burning sulfur, asphalt and pitch on soldiers since at least 200 CE."

"Reminiscent of Aristotle, Jabir proposed... two exhalations: "earthy smoke" (small particles of earth on their way to becoming fire) and "watery vapor" (small particles of water on their way to becoming air). These, he believed, mingled to become the metals. But Jabir modified the Aristotelian approach by proposing that exhalations underwent intermediate transformations into sulfur and mercury before becoming metal. The reason for the existence of different types of metals, he believed, was that the sulfur and mercury were not always pure. He proposed that if the right proportions of sulfur and mercury with the right purity could be found... gold would result."

"Paracelsus' greatest triumph was the use of mercury to treat , the new disease of the day. ...Paracelsus may have heard of the treatment in his travels... or the discovery may have been serendipitous, based on... the extension of the mercury-sulfur theory of the Islamic alchemists to a tria prima... of mercury (soul), sulfur (spirit), and salt (body). But... there is no record of the number of people he adversely affected while experimenting with potions that were not effective, which may have been considerable."

"I am holding... one of the most extraordinary substances known to the human race... sulfur... known... since the dawn of humanity. ...[I]t was found in volcanic regions ...and one of the most remarkable things they found about this yellow solid ...is that it burns."

"It's burning with a blue flame... giving off the most foul and acrid fumes... So there is our "burning stone," which in old English was called brimstone."

"[O]ne of the things that's associated with sulfur and... its compounds is unpleasant smells."

"This is a volcano... that cloud of smoke... is... full of sulfurous fumes..."

"The word sulfur... goes... back to... the Hindu civilization... over 5,000 years ago. They had a word for sulfur... in... Sanskrit... sulvere... the enemy of copper. ...[T]hat is the ...destruction of the copper by the hot sulfur vapors... [T]he copper turns into... ...a black crumbly solid. ...The Latin [derived from sulvere] ...becomes sulphur."

"[S]ulfur beautifully burning in a gas jar full of oxygen... is a blue flame... [W]e now have a jar full of sulfurous fumes... [W]e allow the water to mix... The water has been colored green with a... ... As if by magic, the water... [turns] red and now it's gone yellow. ...[T]he ...gas ...when it reacts with water ...makes ."

"[I]t comes out of... volcanoes. ...[I]n ...human history things ...from underground have had... evil connotations... During the rise of various religions and... cultures sulfur was associated with evil... especially... in Christianity... connotations of hell, damnation... the dark underworld... punishment for... sins. ...[C]onnatations which we today ...know are not true..."

"[W]hen you heat fool's gold... some crushed s... [y]ou can see the appearance of this yellow color, and ...a little bit of crackling... . ...[T]he crystals... are breaking up into a powder ...because when you heat things up, they expand on the outside, but not on the inside. ...The yellow stuff is beginning to collect ...It is sulfur ..."

"[P]yrites is the most widely distributed mineral of sulfur ...the chemical name is iron sulfide. ...It has the formula FeS2 and ...thousands of years ago people ...recognized that when you heat it, you ...make sulfur ..."

"This mineral ...is .... It's lead sulfide. ...Beautiful silver crystals. If you heat this strongly, this too will make sulfur come off."

"There are many other sulfides, but this one is... special... Known in the ancient world as dragon's blood, and the reason... this red color. ...[W]hen they heated this strongly ...(This was particularly well known in ancient China and... in southern Spain.) ...it makes two... remarkable substances. One of them is sulfur... the other... is the liquid metal... mercury. ...[T]his fired up the imagination of ...ancient philosophers ...asking questions about ultimately what are all s made of."

"[T]he great Arabic alchemists... in the 8th or 9th century AD... came up with the idea that ultimately all metals are composed of sulfur and mercury..."

"[T]he sulfur-mercury theory... reasoning was... straightforward. They said... "If you mix this [mercury] with this [sulfur] in the right proportion, you can make any metal.""

"Science is very difficult, and... the ancient world... was... a world of correspondences. ...[S]omething ...could well be ...actually made of things that make it look like something. ...That was the cleverest way ...people used to view the world in those days."

"This sulfur-mercury theory... people continued to believe... for a thousand years."

"I have some beautiful crystals... these green ones and the blue ones... have been observed... [from] water evaporating on the side of lakes... close to volcanoes... [T]hey have... a glassy appearance. ...[T]he Sumerians, 2000 years ago ...described these ...The Latin word for glass is vitriolus [or vitrum] and so glassy substance became known as vitriols. ...[T]he medieval chemists discovered that if you heat these [crystals] very strongly... they give off a... terribly powerful smell and... a liquid which is capable of dissolving... metals. ...It was called oil of vitriol because it came from those glassy substances, but today we call it ."

"[T]he types of substances... made when metals dissolve in [sulfuric] acids...are called s. In the olden language they were called s. ...Here I have some beautiful crystals of copper sulfate ...blue vitriol. ...Here... iron sulfate... iron [or green] vitriol, which is the first sulfate... that they made the... sulfuric acid from, and... some crystals of white vitriol... . ...But I want to show you a most interesting [clear] mineral ...extremely beautiful. ...This comes out of the ground ...[A]lmost everyone ...would have lots of this in your houses. ...The mineral is called . The chemical name is ...[from which] we make plaster. ...Once again sulfur playing a key role in our everyday lives."

"We have wonderful uses of on an everyday basis. ...[J]ust about every ...motorcar [which runs on diesel or on petrol] ...has sulfuric acid ...inside the car battery."

"[T]he fact that sulfur has a low melting point of 115°C... has been exploited in making molds..."

"I'm going to melt the sulfur. ...The ...sulfur has molecules whose formulae are S8 ...They're pocket rings. They're like little crowns. ...[W]hen you get to roughly 160°C ...they break up ...and they start making a . They polymerize, like a plastic. ...I'm going to pour it into some cold water. ...like golden syrup. ...It's what we call plastic sulfur. ...[I]t's neither a liquid nor a solid."

"[the gas produced by burning sulfur]... has been used as a bleach and a fumigant since ancient Egyptian times."

"[A]bout 1,200 years ago... Al Razi... started making ... and... introduced marzipan into Europe... the tradition of using... sulfur for [marzipan] molds..."

"[A]n electric machine... first produced by ... is based on... attractor forces. ...[I]f you take a lump of sulfur and... rub it with a silk cloth... it will start to pick up bits of paper... hair... feather... [A]nother mineral... [Latin electrum]... had the same property. ...Otto von Guericke made a special globe out of sulfur ...and he described the remarkable reactions of things being ...attracted to it ...[I]t was the birth of ..."

"[T]he reason why is so interesting and why... the chemistry of sulfur is so interesting, is because sulfur is a very, very reactive element. Not only is it reactive, but it can form many different kinds of chemical combination..."

"The way we test... for... is to put in a burning splint... and you see it has gone out."

"This gas comes out of volcanoes as well as sulfur dioxide, and... is called . ...It has a phenomenally unpleasant smell of rotten eggs. Apart from that, it's unbelievably poisonous. ...[I]t undergoes an extraordinarily interesting reaction with sulfur dioxide. ...The lower jar is going yellow ...[W]e have made sulfur. ...also ...water. ...Two gases have reacted together to make a solid and a liquid. Secondly, two compounds of sulfur have made the element sulfur... Furthermore... it's... a redox reaction in which sulfur is reduced in one... and oxidized in the other. ...[M]any geologists believe that these two gases come out of volcanoes together and... make huge deposits of sulfur... found at the mouths of volcanoes."

"Sulfur is today obtained mainly from extraction from fossil fuels, from , from gas and from crude oil."

"This is a jar full of sulfur dioxide. ...[W]hen we pour solution, which is purple. ...It's lost its color. Let's try... [yellow] solution... Magic [as it turns ]? No, it's chemistry... [T]he sulfur dioxide is acting as a . It has caused them to change color on account of the change in of from +7 to +2, from +6 to +3."

"[T]here's burning, and... we lower it into sulfur dioxide. It carried on burning for a little while... [I]n sulfur dioxide, magnesium... breaks the bonds between the sulfur and the oxygen... itself becoming ... and releasing a little... sulfur... [T]hat's an example of sulfur dioxide as an ."

"Sulfur dioxide... is... present in many wines. ...Usually ...sulfur dioxide is used as a food preservative, ...but they usually call it ...SO3^2-."

"[S]ulfur is unbelievably reactive. ...Sulfur can form 4 hooks, 2 hooks, -2. s +4, +6 and -2, 0 in... the element..."

"is adding tiny amounts of sulfur to rubber to make it much stiffer. ...If not for ...vulcanization, we'd have no tires ...on motorcars, on airplanes or bicycles. We'd have no hoses in cars and so on... The world would be quite different. Vulcanization was invented by in 1840, one of the most important uses of sulfur today."

"These are the three ingredients in , which were known to the Chinese ...about 1,000 years ago: sulfur, and potassium nitrate. ...[T]hey're used in explosives and fireworks..."

"I have presented the as a kind of travel guide to an imaginary country, of which the elements are the various regions. This kingdom has a geography: the elements lie in particular juxtaposition to one another, and they are used to produce goods, much as a prairie produces wheat and a lake produces fish. It also has a history. Indeed, it has three kinds of history: the elements were discovered much as the lands of the world were discovered; the kingdom was mapped, just as the world was mapped, and the relative positions of the elements came to take on a great significance; and the elements have their own cosmic history, which can be traced back to the stars."

"It was a great achievement of the early chemists—with the crude experimental techniques available also with the ever-astonishing power of human reason... to discover this reduction of the world to its components, the chemical elements. Such reduction does not destroy its charm but adds understanding to sensation, and this understanding only deepens our delight."

"I have raised a question which may be regarded as heretical. At the time when our modern conception of chemistry first dawned... the average chemist... accepted the elements as ultimate facts... absolutely simple, incapable of transmutation or decomposition, each a kind of barrier behind which we could not penetrate. ...[H]e said they were self-existent from all eternity ...But in our times... we cannot help asking what are the elements, whence do they come, what is their signification? ...These elements perplex us in our researches, baffle us in our speculations, and haunt us in our very dreams. They stretch like an unknown sea before us—mocking, mystifying and murmuring strange revelations and possibilities. If I venture to say that... elements are not simple and primordial... but have evolved from simpler matters—or... one sole kind of matter—I... give formal utterance to an idea... for some time "in the air" of science. Chemists, physicists, philosophers of the highest merit declare explicitly their belief that the seventy... elements of our text-books are not the which we must never hope to pass."

"1. Small particles called atoms exist and compose all matter; 2. They are indivisible and indestructible; 3. Atoms of the same chemical element have the same chemical properties and do not transmute or change into different elements."

"That the forms of natural bodies may depend upon different arrangements of the same particles of matter has been a favourite hypothesis advanced in the earliest era of physical research, and often supported by the reasonings of the ablest philosophers. This sublime chemical speculation sanctioned by the authority of Hooke, Newton, and Boscovich, must not be confounded with the ideas advanced by the alchemists concerning the convertibility of the elements into each other. The possible transmutation of metals has generally been reasoned upon not as a philosophical research, but as an empirical process. Those who have asserted the actual production of the precious metals from other elements, or their decomposition, or who have defended the chimera of the philosopher's stone, have been either impostors, or men deluded by impostors. In this age of rational inquiry it will be useless to decry the practices of the adepts, or to caution the public against confounding the hypothetical views respecting the elements founded upon distinct analogies, with the dreams of alchemical visionaries, most of whom, as an author of the last century justly observed, professed an art without principles, the beginning of which was deceit, the progress delusion, and the end poverty."

"[[w:Chlorine|[C]hlorine]] possesses the singular power of removing the of certain bodies, replacing it atom for atom. This law of nature, this law or theory of substitutions... I propose to call... metalepsy, from μετάληψις, which expresses... that the body... has taken one element in place of another, chlorine in place of hydrogen, for example. Thus is formed by substitution, or by metalepsy; it is one of the maleptic products of alcohol. ...acetic ether, , are maleptic products of alcohol."

"Some recent work by E. Fermi and L. Szilard, which has been communicated to me in manuscript, leads me to expect that the element may be turned into a new and important source of energy in the immediate future. Certain aspects of the situation seem to call for watchfulness and, if necessary, quick action on the part of the Administration..."

"Although the problem of transmuting chemical elements into each other is much older than a satisfactory definition of the very concept of chemical element, it is well known that the first and most important step towards its solution was made only nineteen years ago by the late Lord Rutherford, who started the method of the nuclear bombardments."

"[T]he purpose of my paper would be entirely attained if I succeed in turning the attention of investigators to the relationships in the size of the atomic weights of nonsimilar elements, which have, as far as I know, been almost entirely neglected until now."

"No matter how properties of simple bodies may change in the free state, something remains constant, and when the element forms compounds, this something is material existence and establishes the characteristics of the compounds, which include the given element. In this respect we know only one constant peculiar to an element, namely the atomic weight. The size of the atomic weight, by the very essence of matter, is common to the simple body and all its compounds. Atomic weight belongs not to coal or diamond, but to carbon."

"1. The elements, if arranged according to their atomic weights, exhibit an evident periodicity of properties. 2. Elements which are similar as regards their chemical properties have atomic weights which are either of nearly the same value (e.g., platinum, iridium, osmium) or which increase regularly (e.g., potassium, rubidium, caesium). 3. The arrangement of the elements, or of groups of elements in the order of their atomic weights corresponds to their so-called valencies as well as, to some extent, to their distinctive chemical properties--as is apparent among other series in that of lithium, beryllium, barium, carbon, nitrogen, oxygen and iron [sic. The printed speech in J. Chem. Soc. says barium and iron. Obviously boron (B) and fluorine (F) are meant. Mendeleev's 1869 paper lists the symbols B and F rather than the names of the elements.--CJG] 4. The elements which are the most widely diffused have small atomic weights. 5. The magnitude of the atomic weight determines the character of the element just as the magnitude of the molecule determines the character of a compound body. 6. We must expect the discovery of many yet unknown elements, for example, elements analogous to aluminium and silicon, whose atomic weight would be between 65 and 75. 7. The atomic weight of an element may sometimes be amended by a knowledge of those of the contiguous elements. Thus, the atomic weight of tellurium must lie between 123 and 126, and cannot be 128. 8. Certain characteristic properties of the elements can be foretold from their atomic weights. ...[R]elations ...exist between the atomic weights of dissimilar elements ...hitherto ...neglected. I believe that the solution of some of the most important problems of our science lies in researches of this kind. To-day, 20 years after the above conclusions were formulated, they may still be considered as expressing the essence of the now well-known periodic law."

"Hitherto chemists are not agreed upon the number of simple principles or elements, of which all corporeal substances are composed. ...Others believe that earth and phlogiston are those principles which are the constituent parts of all corporeal substances. The greatest number seem to admit only the peripatetic elements."

"The Bakerian lecture in which Davy announces the discovery of the compound nature of the fixed alkalis opens with a reference to the concluding remarks of his lecture of the previous year, "that the new methods of investigation promised to lead to a more intimate knowledge than had hitherto been obtained concerning the true elements of bodies. This conjecture, then sanctioned only by strong analogies, I am now happy to be able to support by some conclusive facts.""

"It was taught by some chemists that an alkali is hidden in every earth, and by others that an alkali is an earth refined by the presence of acid and combustible matter. Black's exact quantitative investigations tended to disparage all such explanations as these; but it yet remained to find the precise composition the alkalis and the earths. Lavoisier thought that these bodies must be compounds; but, as he had no means of proving this, he classed them with the elements, while suggesting that the earths were probably compounds of oxygen with unknown s."

"So let us listen to the light—what music do we hear? For one thing, we can elicit from each chemical element its own, unique chord. You may sometimes have noticed that a bright yellow flash is produced if ordinary table salt is sprinkled on a flame...a first bare hint of the subject of flame spectra... The fact that different elements emit light with different color characteristics is exploited by the makers of fireworks."

"Earth is one of the four simple substances called elements, or primitive principles; because they are indeed the most simple of all those which enter into the combination of compound bodies. We cannot doubt, in particular, that the greatest part of the compounds which we can analyse contain earth as one of their principles; for after art has exhausted all its efforts to decompose them, a fixed and solid matter always remains, upon which no change can be produced; and this is what is generally called earth. It has the solidity, weight, fixity, and other principal properties of the mass of solid matter which forms the globe we inhabit, called also the earth."

"These general considerations are sufficient to convince us, that in nature a substance exists whose properties are different from those of fire, air, water; and which is, like these other substances, one of the elements of compound bodies. But a vague assertion like this does not satisfy chemists. Besides the ascertaining of the exigence of the different substances submitted to their examination, they require to know the properties of these substances in their greatest degree of purity and simplicity; but they have found much difficulty and uncertainty in investigating the essential properties of the purest and simplest terrestrial element."

"Earth is not found so pure as the other elements, fire, air, and water, which, though not entirely free from mixture, are however so pure, that we may certainly and easily discover their fundamental properties. These properties of each of these pure elements are so well ascertained, and so evident, that nobody has yet attempted to distinguish different kinds of fire, air, or water, notwithstanding the differences which may arise from the heterogeneous substances with which they are almost always mixed."

"But we cannot say the same of earth; for a considerable number of substances are called earths, because they possess the principal properties of the terrestrial element: but these substances, when examined more particularly, are always found to differ from each other so much in other respects, and to be so difficultly purifiable from heterogeneous matter, that we have not ascertained whether only one simple and elementary earth, or several ones essentially different, although equally simple, exist."

"The most general and most probable opinion is, that as only one kind of fire, of air, and of water, so only one kind of simple elementary earth, exists. Alchemists chiefly have endeavoured to discover this primary earth, not with an intention to ascertain its properties, but because they imagined that as gold is the purest of metals, the earth of which it is partly composed must be also the most pure; they have, therefore, searched every where for this earth, which they call pure earth and virgin earth. They have endeavoured to obtain it from dew, rain, the air, ashes of vegetables, animals, and several minerals: but it was impossible to find it in compound bodies; for we shall see that when once this element makes part of a compound body, it cannot be disengaged from the substances with which it has united."

"As earth is an element... it deserves an accurate investigation to discover which is the most simple and elementary of all the substances to which the name earth has been applied."

"Van Helmont of ... was formed in the school of Alchemy, and his mind was tinctured with its prejudices: but his views concerning nature and the elements were distinguished by much more philosophical acuteness, and more sagacity, than those of any former writer. He is the first person who seems to have had any idea respecting elastic fluids, different from the air of the atmosphere; and he has distinctly mentioned three of these substances, to which he applied the term es: namely aqueous gas or steam, unctuous or inflammable gas, and gas from wood or carbonic acid gas. Van Helmont developed some accurate views respecting the permanent elasticity of air, and the operation of heat upon it; and a sketch of a curious instrument very similar to the differential thermometer, is to be found in his works."

"Boyle was one of the most active experimenters, and certainly the greatest chemist of his age. He introduced the use of tests or s, active substances for detecting the presence of other bodies: he overturned the [prevalent] ideas... that the results of operations by fire were the real elements of things, and he ascertained... important facts respecting inflammable bodies, s, es, and the phænomena of combination; but neither he nor any of his contemporaries endeavoured to account for the changes of bodies by any fixed principles."

"Beccher, ...after having studied with minute attention, the operations of , and the phænomena of the kingdom, formed the bold idea of explaining the whole system of the earth by the mutual agency and changes of a few elements. And by supposing the existence of a vitrifiable, a metallic, and an inflammable earth, he attempted to account for the various productions of rocks, crystalline bodies, and metallic veins, assuming a continued interchange of principles between the atmosphere, the ocean, and the solid surface of the globe, and considering the operations of nature as all capable of being imitated by art."

"Dr. Hales... resumed the investigations commenced with so much success by Boyle, Hooke, and Mayow; and endeavoured to ascertain the chemical relations of air to other substances, and to ascertain by statical experiments the cases in nature, in which it is absorbed or emitted. ...[B]ut, misled by the notion of one elementary principle constituting elastic matter... he formed few inferences connected with the refined philosophy of the subject..."

"It was felt by many philosophers, particularly by the illustrious Bergman, that an improvement in chemical nomenclature was necessary, and in 1787, Messrs. Lavoisier, Morveau, Berthollet, and Fourcroy, presented to the world a plan for an almost entire change in the denomination of chemical substances, founded upon the idea of calling simple bodies by some names characteristic of their most striking qualities, and of naming compound bodies from the elements which composed them."

"Simplicity and precision ought to be the characteristics of a scientific nomenclature: words should signify things, or the analogies of things, and not opinions. If all the elements were certainly known, the principle adopted by Lavoisier would have possessed an admirable application; but a substance in one age supposed to be simple, in another is proved to be compound; and vice versa. A theoretical nomenclature is liable to continued alterations; oxygenated muriatic acid is as improper a name as dephlogisticated marine acid."

"The attempts made to analyse vegetable substances previous to 1720, merely produced their resolution into the supposed elements of the chemists of those days, namely, salts, Earths, phlegm, and sulphur. Boerhaave and Newmann attempted an examination by fluid menstrua, which was pursued with some success by Rouelle, Macquer and Lewis. Scheele, between 1770 and 1780, pointed out several new vegetable acids."

"Fourcroy, Vauquelin, Deyeux, Seguin, Proust, Jacquin, and Hermbstadt, between 1780 and 1790, in various interesting series of experiments, distinguished between different secondary elements of vegetable matter, particularly extract, , gums, and resinous substances; and investigations of this kind have been pursued with great success by Hatchett, Pearson, Shraeder, Chenevix, Gehlen, Thomson, Thenard, Chevreul, Kind, Brande, Bostock and Duncan. The chemistry of animal substances has received great elucidations from several of the same enquirers; and Berzelius has examined most of their results, and has added several new ones, in a comprehensive work expressly devoted to the subject, published in 1808."

"Experiments made by Richter and Morveau had shewn that, when there is an interchange of elements between two neutral salts, there is never an excess of or basis; and the same law seems to apply generally to double decompositions."

"When one body combines with another in more than one proportion, the second proportion appears to be some multiple or divisor of the first; and this circumstance, observed and ingeniously illustrated by Mr. Dalton, led him to adopt the atomic hypothesis of chemical changes, which had been ably defended by Mr. Higgins in 1789, namely, that the chemical elements consist of certain indestructible particles which unite one and one, or one and two, or in some definite [] numbers."

"Whether a homogeneous substance is an element or a compound can be determined only by a series of quantitative experiments: if it has been separated into two or more homogeneous substances, and formed by the union of two or more homogeneous substances, it is a compound; if it has not been separated into unlike portions, nor formed by the union of unlike substances, it is an element."

"Lavoisier's quantitative examination of the change... proved that the total mass of the reacting substances mercury and air, remained unchanged. ...the masses of the two elements which combine are always in the ratio of one of oxygen to 12.5 of mercury. When the compound mercuric oxide is strongly heated, it is changed into the elements mercury and oxygen; the sum of the masses of the two elements obtained is exactly equal to the mass of the compound changed; the masses of the mercuric oxide, mercury, and oxygen, are always in the ratio of 13.5 to 12.5 to 1."

"The composition of a compound is stated in terms of the elements which unite to form it, and can be obtained by its decomposition."

"In... A New System of Chemical Philosophy published in 1808, John Dalton laid the foundations of the atomic theory: he assumed chemical action to be an action between very minute particles of elements and compounds, and all the minute particles of the same element, or compound, to be exactly the same size and weight. ...his hypothesis assumed the accuracy and universal applicability of those generalisations which are now called the laws of chemical combination."

"All the oldest cosmogonies regarded water as the fundamental principle of things: from Okeanos sprang the gods—themselves deified personifications of the "elements" or principles of which the world was made. ...[T]his doctrine of the origin and essential nature of matter came to be... associated with the name of Thales of Miletus... who, according to Tertullian, is to be regarded as the first of the race of the natural philosophers—that is, the first of those who made it their business to inquire after natural causes and phenomena. Thales... may have been influenced by the Egyptian teaching in the formulation of his cosmological theories."

"Although the idea of a primal "element" or common principle is to be found in every old-world philosophical system, the ancient philosophers were by no means in agreement as to its character. Anaximenes... taught that it was air, Herakleitos of Ephesus that it was fire, and Pherekides that it was earth."

"Empedokles... was the first whose name has come down to us to reintroduce the definite conception of four primal elements—fire, air, water, and earth. These he regarded as distinct, and incapable of being transmuted, but as forming all varieties of matter by intermixture in various proportions. These principles he deified, Zeus being the personification of the element of fire, Here of air, Nestis of water, and Aidoneous of earth."

"The doctrine of the four elements was also adopted by Plato and amplified by Aristotle... [who] exercised an authority almost supreme in Europe during nearly twenty centuries. His influence is to be traced throughout the literature of chemistry long after the time of Boyle. It may be detected even now. ...His theory of the nature of matter is contained in his treatise on Generation and Destruction. It mainly differed from that of Empedokles in regarding the four "elements" as mutually convertible. Each "element" or principle was regarded as being possessed of two qualities, one of which was shared by another element or principle.Thus: Fire is hot and dry; air is hot and wet; water is cold and wet; earth is cold and dry. In each primal "element" one quality prevails. Fire is more hot than dry; air is more wet than hot; water is more cold than wet; earth is more dry than cold. ...[I]f the dryness of fire is overcome by the moisture of water, air is produced; if the heat of air is overcome by the coldness of earth, water is formed; if the moisture of water is overcome by the dryness of fire, earth results. Ancient chemical literature contains many illustrations or diagrams symbolising the convertibility or mutual relations...."

"The supremacy of the old philosophy may be said to have been first distinctly challenged by Robert Boyle. The appearance in 1661 of his book, The Sceptical Chemist, marks a turning-point in the history of chemistry. ...In this treatise Boyle sets out to prove that the number of the peripatetic elements or principles hitherto assumed by chemists is, to say the least, doubtful."

"He concludes... that the Paracelsian elements—their "salt," "sulphur," and "mercury"—are not the first and most simple principles of bodies; but that these consist, at most, of concretions of corpuscles or particles more simple than they, and possessing the radical and universal properties of volume, shape, and motion."

"Boyle was the first to formulate our present conception of an element in contradistinction to that of the Greeks and the schoolmen who influenced the theories of the iatro-chemists. In the sense understood by him, the Aristotelian elements were not true elements, nor were the salt, sulphur, and mercury of the school of Paracelsus."

"He was... the first to define the relation of an element to a compound, and to draw the distinction we still make between compounds and s."

"Prior to the time of Black all forms of gaseous substance were regarded as substantially identical in fact, as being air, as understood by the Ancients a simple elementary substance. It was Black's study of which first clearly established that there were essentially distinct varieties of gaseous matter."

"[Humphry Davy] early began to experiment on , and soon succeeded in developing the fundamental laws of electro-chemistry; and in 1807 he effected the decomposition of [[w:Potassium hydroxide|[caustic] potash]] and [[w:Sodium hydroxide|[caustic] soda]] by the application of voltaic electricity thereby establishing... that the alkalis are compound substances. He subsequently proved that this was also the case with the alkaline earths. Davy thus added some five or six metallic elements to those already known."

"Chemists seemed to be of Turner's opinion that the time had arrived for reviewing their stock of information, and for submitting the principal facts and fundamental doctrines to the severest scrutiny. Their activity was employed not so much in searching for new compounds or new elements as in examining those already discovered. The foundations of the atomic theory were being securely laid. The ratios in which the elements of known compounds are united were being more exactly ascertained. The efforts of workers, Graham excepted, seemed to be spent more on points of detail, on the filling-in of little gaps in the chemical structure, as it then existed, than in attempts at new developments."

"It was largely through the influence of [the following] master-minds that chemistry took a new departure. Prior to their time organic chemistry hardly existed as a branch of science: organic products, as a rule, were interesting only to the pharmacist mainly by reason of their technical or medicinal importance. But by the middle of the nineteenth century the richness of this hitherto untilled field became manifest, and scores of workers hastened to sow and to reap in it. The most striking feature, indeed, of the history of chemistry during the past sixty years has been the extraordinary expansion of the organic section of the science. The chemical literature relating to the compounds of now exceeds in volume that devoted to all the rest of the elements."

"[] worked in every field of chemistry. He invented many analytical processes, established the gravimetric composition of water and of air, and revised the atomic weights of the greater number of the elements then known."

"Mercury doesn't contribute its valence electrons readily to the [electron] soup. The thinner soup can't bind the mercury atoms together very strongly. Mercury atoms easily slip past and away from each other. Heat easily overcomes the weak binding between mercury atoms, and mercury boils and melts at lower temperatures than any other metal. Because the valence electron soup is thinner for mercury, its electrical and thermal conductivity are poor."

"While Paracelsus was pressing his doctrines on all sides, and endeavouring to lead chemistry into a new channel, another, Agricola, was quietly at work among the mines of Saxony, utterly indifferent to all but the advance of his science. It is to Agricola's systematic observations that we trace the beginnings of the science of mineralogy. In metallurgy, also, he was a pioneer, the first to give a clear and succinct account of the preparation of many metals. He taught the condensation and purification of sulphur given off during the roasting of many s, the separation of silver from gold by means of nitric and sulphuric acid, the preparation of such bodies as salt, , and saltpetre on a large scale. The apparatus described by Agricola and employed by him for the and testing of ores were still in use at the end of the eighteenth century. Agricola stands out solitary among the men of his time as one pursuing chemistry from pure love of the science; his work had no other aim than the increase of knowledge."

"Iron yields to certain degrees of beatings or repeated pressure; its impenetrable molecules, purified by man and made homogeneous, disintegrate; and, without being in fusion, the metal no longer has the same virtue of resistance. Marshals, locksmiths, tool makers, all the workers who constantly work this metal then express the state of it by a word of their technology: "The iron is retty!" they say, appropriating this expression exclusively devoted to hemp, the disorganization of which is obtained by retting. Well, the human soul, or if you will the threefold energy of body, heart, and spirit, is in an iron-like situation, as a result of certain repeated shocks. It is thus with men like hemp and iron — they are retty."

"A neutral salt, which is composed of an acid and alkali, does not possess the acrimony of either of its constituent parts. It can easily be separated from water, has little or no effect upon metals, is incapable of being joined to inflammable bodies, and of corroding and dissolving animals and vegetables; so that the attraction both of the acid and alkali for these several substances, seems to be suspended till they are again separated from one another."

"One worker on one of the supports... either manually or with a trowel distributes the mortar over the chicken wire... Simultaneously, another worker from within the room... holds the mortar which is applied from the outside with a metal float or trowel in order that the mortar does not fall. Once this operation is completed, the required finish is applied both from the outside and the inside."

"The export of into Italy was strictly forbidden; but aluminium was almost the only metal that Italy produced in quantities beyond her own needs. The importation of scrap iron and into Italy was sternly vetoed in the name of public justice. But as the Italian metallurgical industry made but little use of them, and as steel billets and were not interfered with, Italy suffered no hindrance. Thus, the measures pressed with so great a parade were not real sanctions to paralyse the aggressor, but merely such half-hearted sanctions as the aggressor would tolerate, because in fact, though onerous, they stimulated Italian war spirit. The League of Nations, therefore, proceeded to the rescue of Abyssinia on the basis that nothing must be done to hamper the invading Italian armies. These facts were not known to the British public at the time of the election. They earnestly supported the policy of the sanctions, and believed that this was a sure way of bringing the Italian assault upon Abyssinia to an end."

"The Franklin sold at £4. 6s, each at the furnace, and at Philadelphia £18 per ton, the price varying with the metal."

"The art of tempering and iron developed in India long before its known appearance in Europe; , for example, erected at Delhi (ca. 380 A.D.) an iron pillar that stands untarnished today after fifteen centuries; and the quality of metal, or manner of treatment, which has preserved it from rust or decay is still a mystery to modern metallurgical science. Before the European invasion the smelting of iron in small charcoal furnaces was one of the major industries of India. The Industrial Revolution taught Europe how to carry out these processes more cheaply on a larger scale, and the Indian industry died under the competition. Only in our own time are the rich mineral resources of India being again exploited and explored."

"[T]here are not really 2-dimensional metals because conventional metals, for physics reasons... don't really like to be in the 2-D state, and most of them immediately oxidize anyway... So by discovering ... we created materials which are 2-dimensional metals. So we... closed the gap in existing the series of materials."

"Tradition has it that not only concerned himself with the unification of Egypt but also with the control of the river: to him is attributed the first damming of the Nile, the digging of dikes for agricultural purposes and indeed the first attempt to control and apportion the waters of the river. The wealth of Egypt was thus, with , based upon its agricultural output. However, unlike Mesopotamia, the Egyptians had on their doorstep a number of mineral resources that they were able to exploit with little effort, including copper ores, gold and a wide range of rocks suitable for building and the making of a wide variety of ornaments. [S]hortly before the year 3000 metallurgists made a discovery that was to transform the entire "industry." ...by mixing a small quantity of tin ore with the copper ores when... smelted... they discovered the alloy . The occurrence of tinstone... does not occur in the same type of deposit as do the ores of copper, but rather, [near] veins of gold. ...Thus tinstone ...may well have been noticed during washing for gold... finding that the little black lumps of ore were relatively heavy, presumably made various attempts at smelting them until they arrived empirically at a suitable alloy... [T]he effect is to reduce the melting point... they had a far more fluid metal that was much easier to cast. ...the quality of casting improved dramatically."

"Aristotle had considered metals to be formed by the combination of moist and dry exhalations, and in the Jabirian works these... are... vapours of mercury and sulphur. The cause of the different metals was the... quality of the sulphur... The term sulphur ...as a component of metals probably referred to a volatile combustible material to which no... substance corresponded exactly. Likewise mercury... may... have been... an approximation to the other volatile liquid component of metals. ...The notion that metals contained a combustible principle persisted, and... provided the inspiration for the phlogiston theory."

"The Jabirian alchemists... believed that metals were ultimately composed of the four Aristotelian elements earth, water, air and fire... A base metal had to be treated with a medicine or elixir to adjust... qualities... with the proportions of gold. ...[Q]ualities of heat, cold, moisture and dryness could each be separated in pure form. ...First they subjected various organic materials to ... which often resulted in... a volatile combustible... (air), a liquid (water), a combustible tarry material (fire) and a dry residue (ash). [Each of] [t]hese elements were supposed... composed of two qualities, and... could be isolated by... purification. Thus water... could be converted into pure cold by repeated distillation... and further [distillations] in the presence of a drying agent. The resulting pure cold... a brilliant white solid."

"My invention shows a new product which helps to replace timber where it is endangered by wetness, as in wood flooring, water containers, plant pots, etc. The new substance consists of a metal net of wire or sticks which are connected or formed like a flexible woven mat. I give this net a form which looks in the best possible way, similar to the articles I want to create. Then I put in hydraulic cement or similar bitumen tar or mix, to fill up the joints."

"Nothing can vex the Devil more Than the name of him whom we adore. Therefore doth it delight me best To stand in the choir among the rest, With the great organ trumpeting Through its metallic tubes, and sing: Et verbum caro factum est! [And the Word was made flesh!] These words the devil cannot endure, For he knoweth their meaning well! Him they trouble and repel, Us they comfort and allure, And happy it were, if our delight Were as great as his affright!"

"In the history of war and society we single out three main innovations to describe significant changes before 1800: the introduction of metal, when humans abandoned stone weapons for ones made from and iron; the domestication of the horse, which gave warriors greater mobility and speed; and the introduction of , which transformed war on land and at sea. (Since other parts of the world, such as the Americas, did not have horses until the Europeans brought them in the sixteenth century and some parts of the world, such as Australia, never developed metal weapons, not all human societies have experienced change at the same time.) In each case, of course, many other things were happening both to technology and to society. Metal weapons were only a part of the story: societies had to develop the soldiers and the infrastructures to make use of them. Horses were more formidable when the enabled them to pull s or later on when they could carry armed warriors. The introduction of gunpowder too was accompanied by other important developments: in metallurgy, for example, so that guns did not explode when they were fired, or in the design and navigation of ships, so that they could make use of the new cannon."

"The metals are all essentially identical; they differ only in form. Now, the form brings out accidental causes, which the experimenter must try to discover and remove, as far as possible. Accidental causes impede the regular union of sulphur and mercury; for every metal is a combination of sulphur and mercury. A diseased womb may give birth to a weakly, leprous child, although the seed was good; the same is true of the metals which are generated in the bowels of the earth, which is a womb for them; any cause whatever, or local trouble, may produce an imperfect metal. When pure sulphur comes in contact with pure mercury, after more or less time, and by the permanent action of nature, gold is produced."

"Mercury as a liquid metal is capable of dissolving other metals and forming metallic solutions. These are generally called 'amalgams.' The formation of these solutions is often accompanied by the development of a large amount of heat—for instance when and sodium are dissolved... but sometimes heat is absorbed, as... when is dissolved. ...[T]he solution of metals in mercury is accompanied by the formation of definite chemical compounds of the mercury with the metals dissolved. ...[I]n many cases such compounds have undoubtedly been obtained, and their existence is clearly shown by the evident crystalline structure and characteristic appearance of many amalgams."

"Sonorous metal blowing martial sounds, At which the universal host up sent A shout that tore hell's concave, and beyond Frighted the reign of Chaos and old Night."

"Few would defend a small view of Alchemy as "Mother of Chemistry", and confuse its true goal with those external metal arts. Alchemy is an erotic science, involved in buried aspects of reality, aimed at purifying and transforming all being and matter. Not to suggest that material operations are ever abandoned. The adept holds to both the mystical and physical work."

"The history of science may be described as the breaking down, and the crumbling away, of artificially constructed barriers. All the great men of science have been famous wall-breakers. ...It is worthy to remark that the central conception of the alchemists ...was the unity of natural phenomena. ...[T]heir arguments would be somewhat as follows—Plants grow from seeds ...animals become larger, stronger, and more complete ...the plant may well be called more perfect than the seed, and the full grown animal more perfect than the immature ...both plants and animals grow, come to their prime, and decay; and there are degrees of perfection in the animal and vegetable worlds. Now—we may suppose the argument of the alchemist... minerals and metals and all inanimate things should grow, and change, from less perfect to more perfect forms; as there are degrees of perfectness and dignity in among all living things, so... among all things; some metals disappear in acrid liquids, and... are... easily worn away, they are readily melted and burnt to ; but some other metals are not swallowed up by corrosive liquids, nor... worn away with ease, nor readily changed in fire; there are evidently noble and base metals, perfect and imperfect metals; and as the less perfect seed... produces the more perfect plant... rendered yet more perfect by cultivation, so the imperfect metals change slowly into... more perfect, and this... can be hastened by man's art and devices. ...[L]iving things are more perfect that inanimate things ...[M]uch more must changes from immature to mature forms be constantly proceeding from dead things like minerals and metals ...[I]t is probable that the plasticity of the minerals and metals will be greater ...hence ...it will be a comparatively easy thing to grow a noble metal like gold from ignoble metals like and copper, although it is impossible to change one kind of animal into another or one sort of plant into another ... A vague conception of the unity of nature... led to little accurate knowledge..; all that could be done was to perform a vast number of inaccurate and incomplete experiments, and to state the results in loose and slipshod language of the vague but sonorous hypothesis which prompted the experiments. And so although the hypothesis postulated the unity of nature there was no unity in the experimental results... collected to support the hypothesis. ...A man who sets out to discover what is must endeavour to put aside all his notions of what ought to be; it is only when he has gained a solid foundation of verified and accurate facts that he may venture to make a definite guess concerning the cause ...but unless he makes clearly stated guesses ...scientific hypotheses—he will remain a mere collector of half facts ..."

", The Story of the Chemical Elements (1897) pp. 16-19."

"RECOMMENDATION 6: Ferrocement in Disaster Relief. After fires, floods, droughts, and earthquakes... [t]ransportation is often disrupted... Supplies of bulky conventional building materials may be stranded outside the disaster area, whereas the basic ingredients of ferrocement may be available on the site or easily transported. The versatility of ferrocement also reduces logistical supply problems: wire mesh, cement, sand, and water can be substituted for the metal used for roofing, woods or plastic for shelters and clinics, asphalt for helipads, steel for bridges, and so on. Moreover, most ferrocement structures, though built for an emergency, will last long after the emergency is over. ...[F]errocement could be used at a disaster site for many purposes: Transport facilities, from simple boats to barges, docks, marinas, helipads, and simple floating bridges or short footbridges as well as road repairs. ...Food-storage facilities, quickly designed to local needs and quickly built, to preserve emergency food supplies. ...Emergency shelters such as, for example, the quonset type of roof, which is easy to erect and highly efficient. ..Public health facilities, such as latrines and clinics, built with ferrocement roofs and stucco-type walls of the same wire mesh and mortar. ...[C]adres of ferrocement workers could be trained in emergency applications and the supervision of local laborers at the disaster site."

"From this epocha the hypothesis of the tria prima seems wholly to have been abandoned: whilst a very different doctrine was proposed by Beccher in his Physica Subterranea [1669], and to which we are perhaps indebted for the present advanced state of chemical science; since he was the first to point out chemical analysis as the only true method of ascertaining the elements of bodies. According to his doctrine, all terrestrial bodies are composed of water, air, and three earths; viz. the fusible, the inflammable or sulphureous, and the mercurial. The three earths, combined in nearly equal proportions, compose the metals: when the proportion of mercurial earth is very small, they compose stones; when the fusible predominates, the resulting compounds are the precious stones; when the sulphureous predominates, and the fusible is deficient, the compounds are the calorific earths: fusible earth and water compose an universal acid, very much resembling sulphuric acid, from which all other acids derive their acidity; water, fusible earth, and mercurial earth, constitute common salt; sulphureous earth and the universal acid form sulphur. Such was the theory of Beccher, which was afterward considerably modified by Stahl."

"I've noticed that people who have never worked with steel have trouble seeing this... that the motorcycle is primarily a mental phenomenon. They associate metal with given shapes... pipes, rods, girders, tools, parts... all of them fixed and inviolable, and think of it as primarily physical. But a person who does machining or foundry work or forge work or welding sees "steel" as having no shape at all. Steel can be any shape you want if you are skilled enough, and any shape but the one you want if you are not."

"Alchemical theory was essentially static throughout the medieval period. ...Paracelsus was the herald of a new era, an era of . His contribution to alchemical theory lay in the addition to sulphur and mercury of a third principle, which he called '.' Materially this was recognised as the principle of uninflammability and fixidity. ...[T]he tria prima, or three 'hypostatical principles' could be interpreted in either a material or a spiritual sense. In the words of Paracelsus himself: 'Know, then, that all the seven metals are born from a threefold matter... Mercury is the spirit, Sulphur is the soul, and Salt is the body... the soul... unites those two contraries, the body and spirit, and changes them into essence.' ...similar to the material effect of the liquid menstruum, or Hermetic Stream, in uniting sophic sulphur and sophic mercury to produce the Philospher's Stone."

"It seemed probable that the large activity of some of these minerals, compared with and , was due to the presence of small quantities of some very active substance, which was different from the known bodies thorium and uranium. This supposition was completely verified by the work of M. and Mme Curie, who were able to separate from pitchblende by purely chemical methods two active bodies, one of which in the pure state is over a million times more active than the metal uranium. This important discovery was due entirely to the property of radio-activity possessed by the new bodies. The only guide in their separation was the activity of the products obtained. ...The activity of the specimens thus served as a basis of rough qualitative and quantitative analysis, analogous in some respects to the indication of the spectroscope."

"The magnetism as exhibited in iron is an isolated phenomenon in nature. What it is that makes this metal behave so radically different from all other materials in this respect has not yet been ascertained, though many theories have been suggested. As regards magnetism, the molecules of the various bodies behave like hollow beams partly filled with a heavy fluid and balanced in the middle in the manner of a see-saw. Evidently some disturbing influence exists in nature which causes each molecule, like such a beam, to tilt either one or the other way. If the molecules are tilted one way, the body is magnetic; if they are tilted the other way, the body is non-magnetic; but both positions are stable, as they would be in the case of the hollow beam, owing to the rush of the fluid to the lower end. Now, the wonderful thing is that the molecules of all known bodies went one way, while those of iron went the other way. This metal, it would seem, has an origin entirely different from that of the rest of the globe. It is highly improbable that we shall discover some other and cheaper material which will equal or surpass iron in magnetic qualities."

"[M]etals remained the alchemists' chief concern... they seemed in their own way alive, whereas the calces (s) from which they were manufactured crumbled to dust and looked like cinders. Theory at once suggested a natural analogy. The metal was formed from the calx by the incorporation of or spirit; and this theory of metal-formation long remained in favour, being revived around 1700 as the 'phlogiston' theory. The central problem about metals was to identify the volitile constituents which combined with the calces to form the finished metal. For a long time, the status of quicksilver was ambiguous... resembling much more the volatile reagents which corrode metallic surfaces: mercury, in fact, forms an amalgam with other metals, and is even capable of dissolving gold... So the Alchemy of Avicenna classed mercury as a 'spirit' rather than a 'body'..."

"Theophrastus, the successor of Aristotle, ...says, in the beginning of his book on fossils, 'stones are produced from earth, metals from water.' ...Theophrastus is perhaps the best observer among the ancients, whose works are in our possession, and [his] theories... cannot be considered as an unfavourable specimen of the theoretical physics of the age."

"[E]early chemical discoveries led to the pursuit of alchemy, the objects of which were to produce a substance capable of converting all other metals into gold: and an universal remedy calculated indefinitely to prolong the period of human life."

"The processes supposed to relate to the transmutation of metals, and the , were probably first made known to the Europeans during the time of the ..."

"Arnald of Villa Nova... was one of the earliest European inquirers who attended to chemical operations. ...[H]e firmly believed in the transmutation of metals; the same opinions are attributed to him and to Geber; and he seems to have followed the study with no other views than those of preparing medicines, and attempting the composition of the philosopher's stone."

"Beccher, ...after having studied with minute attention, the operations of , and the phænomena of the kingdom, formed the bold idea of explaining the whole system of the earth by the mutual agency and changes of a few elements. And by supposing the existence of a vitrifiable, a metallic, and an inflammable earth, he attempted to account for the various productions of rocks, crystalline bodies, and metallic veins, assuming a continued interchange of principles between the atmosphere, the ocean, and the solid surface of the globe, and considering the operations of nature as all capable of being imitated by art."

"had been used to tinge glass in in the sixteenth century; but the metal was unknown till the time of Brandt, and this celebrated Swedish chemist discovered it in 1733."

"The properties of , which was announced as a peculiar metal by Kaim in 1770, were minutely investigated by Scheele and Bergman a few years after."

"Scheele discovered in 1781; and soon after a metal was extracted from it by Messrs. Fausto & Juan José] D' Elhuyars."

"Platina had been brought into Europe and examined by Lewis in 1749 and in 1803, Descotils, Fourcroy, and Vauquelin announced a new metallic substance in it; but the complete investigation of the properties of this extraordinary body was reserved for Messrs. Tennant and Wollaston, who in 1803 and 1804 discovered in it no less than four new metallic substances, besides the body which exists in it in the largest proportion, namely, iridium, osmium, palladium, and rhodium."

"By researches, the commencement of which is owing to Messrs. Nicholson and Carlisle, in 1800, which were continued by Cruickshank, Henry, Wollaston, Children, Pepys, Pfaff, Desormes, Biot, Thenard, Hissinger, and Berzelius, it appeared that various compound bodies were capable of decomposition by electricity; and experiments, which it was my good fortune to institute, proved that several substances which had never been separated into any other forms of matter in the common processes of experiment, were susceptible of analysis by electrical powers; in consequence of these circumstances, the fixed es and several of the earths have been shewn to be metals combined with oxygene; various new agents have been furnished to chemistry, and many novel results obtained by their application, which at the same time that they have strengthened some of the doctrines of the school of Lavoisier, have overturned others, and have proved that the generalizations of the Antiphlogistic philosophers were far from having anticipated the whole progress of discovery."

"From the first discovery of the production of metals from rude ores, to the knowledge of the bleaching liquor, chemistry has been continually subservient to cultivation and improvement."

"The relations of the common metals to the bases of the alkalies and earths, and the gradations of resemblance between the bases of the earths and s, point out as probable a similarity in the constitution of all inflammable bodies; and there are not wanting experiments, which render their possible decomposition far from a chimerical idea."

"The whole work was done under conditions of great mental excitement. His cousin ,.. his assistant, relates that when he [Humphrey Davy] saw the minute globules of the quicksilver-like metal burst through the crust of potash and take fire, his joy knew no bounds; he actually danced about the room in ecstasy, and it was some time before he was sufficiently composed to continue his experiments. The rapidity with which he accumulated results after this first feeling of delirious delight had passed was extraordinary."

"Before the middle of November he had obtained most of the leading facts. In a letter dated November 13th he tells W. H. Pepys—"

"He had observed that although potash when dry is a nonconductor, it readily conducts when it becomes damp by exposure to air, and in this state "fuses and decomposes by strong electrical powers.""

"It is frequently stated that Davy was enabled to isolate the metals of the alkalis because of the large and powerful voltaic battery which he had at his disposal in the Royal Institution. This is not correct. The battery he employed was of very moderate dimensions, and not by any means extraordinary in power. It was the success he thus achieved that caused the large battery, which is probably referred to, to be constructed, by special subscription, in 1809."

"It would seem from his description of its properties that the potassium he obtained was most probably alloyed with sodium derived from impure potash. Potassium is solid up to 143° F.; but, as Davy subsequently found, an alloy of potassium and sodium is fluid at ordinary temperatures. ...When the potassium was exposed to air its metallic lustre was immediately destroyed, and it was ultimately wholly reconverted into potash by absorption of oxygen and moisture."

"The "basis" of potash at 50° F. was a soft and malleable solid with the lustre of polished silver."

"It may be converted into vapour at a temperature approaching a red-heat, and may be distilled unchanged; it is a perfect conductor of electricity and an excellent conductor of heat. Its most marked difference from the common run of metals was its extraordinarily low specific gravity."

"Although no great stress can be laid on numbers so obtained, they serve to indicate that Davy had not yet obtained the pure metal."

"The "basis" of soda is described as a white opaque substance of the lustre and general appearance of silver. It is soft and malleable, and is a good conductor of heat and electricity. Its specific gravity was found by flotation in a mixture of oil of sassafras and naphtha... It was found to fuse at about 180° F. (the real melting point of sodium is 197.5°). Its action on a number of substances—oxygen, , water, etc.—is then described, and its general behaviour contrasted with that of the "basis" of potash."

"He then enters upon some general observations on the relations of the "bases" of potash and soda to other bodies."

"He begins by again drawing attention to the various surmises which had been made respecting the true nature of potassium and sodium. Although these substances had been isolated, and in the hands of chemists for upwards of two years, their properties were so extraordinary when compared with those of the metals in general, that many philosophers hesitated to consider them as true metals."

"The general properties and chemical activities of and sodium are so very similar that as a matter of commercial production that metal which can be most economically obtained is necessarily the one most largely manufactured, and of the two that metal is sodium. To-day, sodium is made by thousands of tons, and by a process which in principle is identical with that by which it was first made by Davy, i.e., by the of fused caustic soda."

"[A]fter a series of revolutions in its manufacture, sodium, having been produced from time to time on a manufacturing scale by a variety of metallurgical methods involving purely thermal processes of reduction and distillation, entirely dissociated from electricity, we should have now got back to the very principle of the process which first brought the metal to light. And that this has been industrially possible is entirely owing to another of Davy's discoveries - possibly indeed the greatest of them all—Michael Faraday."

"Before me, stretching down to the river, was the factory where a score of workers, clad in helmets and gauntlets and swathed like so many Knights Templar, travel-stained and war-worn, their visages lit up by the yellow soda flames, and their ears half-deafened with the sound of exploding —a veritable inferno—were repeating on a Gargantuan scale the little experiment first made a century ago in the cellars of this building; turning out, day and night, hundredweights of the plastic metal in place of the little pin-heads which then burst upon the astonished and delighted gaze of Davy."

"Even before the appearance of The Sceptical Chemist there was a growing conviction that the old hypotheses as to the essential nature of matter were inadequate and misleading. ...[T]he four "elements" of the Peripatetics had become merged into the tria prima—the "salt," "sulphur," and "mercury"—of the Paracelsians. As the phenomena of chemical action became better known... the conception of the tria prinui, as understood by Paracelsus and his followers, was incapable of being generalised into a theory of chemistry. Becher, while clinging to the conception of three primordial substances as making up all forms of matter, changed the qualities hitherto associated with them. According to the new theory, all matter was composed of a mercurial, a vitreous, and a combustible substance or principle, in varying proportions, depending upon the nature of the particular form of matter. When a body was burnt or a metal calcined, the combustible substance—the terra pinguis of Becher—escaped."

"Other metals, like lead and mercury, did not appear to burn; but on heating them they gradually lost their metallic appearance, and became converted into calces. This operation was known as . In the act of burning or of calcination phlogiston was expelled. Hence metals were essentially compound: they consisted of phlogiston and a calx, the nature of which determined the character of the metal. By adding phlogiston to a calx the metal was regenerated. Thus, on heating the calx of or of with , or , or wood, metallic zinc or lead was again formed. When a candle burns, its phlogiston is transferred to the air; if burned in a limited supply of air, combustion ceases, because the air becomes saturated with phlogiston."

"Some of the alchemists had discovered that a metal gained, not lost, weight by . This was known as far back as the sixteenth century. It had been pointed out by Cardan and by Libavius. Sulzbach showed that such was the case with mercury. Boyle proved it in the case of tin, and Rey in that of lead. Moreover, as knowledge increased it became certain that Stahl's original conception of the principle of combustion as a ponderable substance he imagined, with Becher, that it was of the nature of an earth was not tenable. The later phlogistians were disposed to regard it as probably identical with . But even hydrogen has weight, and facts seemed to require that phlogiston, if it existed at all, should be devoid of weight."

"[T]he writings and labours of the alchemists were both extensive and important. ...[T]heir studies, although misdirected, were not... haphazard. The alchemists had a definite, and... logical, system of philosophy... [T]hey recognised—(1) the unity of matter; (2) the three principles—philosophical mercury, sulphur, and salt; (3) the four elements—fire, air, water, and earth; and (4) the seven metals—gold, silver, mercury, copper, , tin, and ."

"[W]hen an alchemist converted a metal into its oxide, or, as they expressed it, "made a " of it, he thought he had volatilised its mercury and fixed its sulphur. When he distilled ordinary mercury and found a solid residue in the , he called it the "sulphur" of mercury; when he found a sublimed product in the receiver (mercury bichloride), he termed it the "mercury" of mercury or "corrosive sublimate.""

"The more logical mind of Artephius Longaevus introduced a modification of this theory. He distinguished two properties in a metal—the visible and the occult. The former, comprehending its colour, lustre, extension, and other properties visible to the eye, he called its "sulphur"; the latter, comprehending its fusibility, malleability, volatility, and other properties not visible until after... special treatment, he called its "mercury.""

"The mercury of a metal... represented its lustre, volatility, fusibility, and malleability; the sulphur of the metal, its colour, combustibility, affinity, and hardness."

"The salt of the was merely a means of union between the mercury and the sulphur, just as the vital spirit in man unites soul and body. It was doubtless devised to impart a triple form to the idea, in conformity with the method of the theological schoolmen."

"At a still later date [post-16th century] it was argued that exact and natural sciences proceed by induction and deduction, and occult and spiritual sciences by analogy. Following out this line of thought the alchemists produced the following remarkable trilogy:—"