Technology

"The 1967 General Conference on Weights and Measures defined the of time, the second, based on an atomic transition—specifically, between two hyperfine levels of the ground state of cesium-133. (See Physics Today, August 1968, page 60.) Although Cs atomic clocks remain the standard, their time might be running out. Their underlying atomic transition is excited by radiation with a microwave frequency around 9 × 109 Hz, and after decades of advances, a Cs clock’s frequency can be measured with a fractional uncertainty Δν/ν0 of about one part in 1016. But clocks based on optical transitions operate at frequencies around 1014 Hz, which gives them an advantage in the push for lower uncertainty. (See the article by James Bergquist, Steven Jefferts, and David Wineland, Physics Today, March 2001, page 37.) The current record, 9.4 × 10−19, was set in 2019 by an aluminum ion–based optical atomic clock at ."

"... Early clocks were inaccurate by as much as half an hour a day, and had to be reset frequently with the aid of a ; breakdowns were numerous. The energies of the early masters seem to have gone as much into ornamenting their clocks as into making them more precise, for the construction of human and animal automata, as well as astronomical indicators, was quite popular. Finally, in the seventeenth century, the Dutch scientist Christian Huygens created the that resulted in a vast improvement in precision. By then the clock was ingrained in the European way of thinking as the artificial model of the cyclical processes of nature, and it was ready to serve as the prototype for the mechanization of a variety of tasks that had previously been performed by hand."

"Wootz was the first high-quality steel made anywhere in the world. According to reports of travelers to the East, the Damascus swords were made by forging small cakes of steel that were manufactured in Southern India. This steel was called wootz steel. It was more than a thousand years before steel as good was made in the West."

"Damascus steel actually consists of an extremely high-carbon cast steel, the best swords being forged in Iran from cakes of steel made in India and known as wootz."

"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."

"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."

"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."

"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."

"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."

"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."

"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."

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

"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."

"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!"

"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."

"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."

"[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."

"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."

"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."

"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 ..."

"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 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."

"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."

"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."

"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:—"

"[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.""

"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."

"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.""

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

"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."

"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."

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

"[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."

"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."

"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."

"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."

"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."

"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."

"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."

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