chemistry

"[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."

"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."

"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."

"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."

"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."

"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."

"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..."

"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.""

"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."

"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 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."

"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."

"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."

"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."

"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."

"[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."

"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."

"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."

"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."

"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."

"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."

"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."

"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."

"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."

"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."

"[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."

"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."

"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 ..."

"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 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."