THE DISCOVERY OF THE ELEMENTS. 111. SOME EIGHTEENTHCENTURY METALS* MARYE~vrnaWEEKS,THEUNIVERSITY
OF
KANSAS, LAWRENCE, KANSAS
Among the metals isolated in the eighteenth century may be mentioned zinc, cobalt, nickel, and manganese, the h t three of which werediscoveredin Sweden. The researches of Marzgraf, Georg Brandt, Cronstedt, and Gahn which led to the recognition and isolation of these elements were scientific contributions of the first rank, and the personalities of these great men are well worthy of study and emulation. Other mefals of this period will be discussed in later chapters. . . . . . . "Knowing how contented, free and joyful i s life i n the realms of science, one fervently wishes that many would enler their portals." (1).
Zinc Centuries before zinc was discovered in the metallic form, its ores were used for making brass. Ancient metallurgists probably lost this volatile metal as vapor because their apparatus was not designed for condensing it. E. 0. von Lippmann, a famous authority on the early history of science, searched the writings of Aristotle, Pliny, and Dioscorides in vain for any mention of it, but an idol containing 87.5% of that metal was found in a,prebistoric Dacian ruin a t Dor.. dosch, Transylvania (2). P. C. Ray states that the Hindu king, Madanaoils.. recoenized zinc as a metal as early as 1374 (3), and it is probable that the art of smelting the ores originated in India and was carried first to China. A Chinese book entitled "Tien kong kai ou" printed in 1637 From Buggc's "Dar Burh drr grossen Ckcrnikcr" describes the metallurgy and uses of A~~~~~ SxorsMuNo M~~~~~ 1709-1782 this metal (2). German chemist who distinguished A hundred years before zinc was between potash and soda, realized that smelted in Europe, it was being sold oxide now contains the known as alumina, recognized mag- there by Portuguese traders who
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nesia, isolated zinc from calamine, and discovered sugar in the beet.
brought i t from the Orient (4). Georgius Agricola mentioned the formation of "zincum" in the furnaces in Silesia. Small amounts of metallic zinc were obtained as a by-product of the lead industry a t Goslar, Prussia, and G. E. Lohneyss described the process as follows: "The metal zinc or *Illustrations by F.B . Dains, The University of Kansas. Lawrence, Kansas. 22
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counterfeht is formed under the smelting furnaces and in the crevices of the wall where the bricks are not well plastered. When the wall is scraped, the metal falls down into a trough placed to receive it. The metal is not much valued, and the workmen collect it only when they are promised Trinkgeld" (Z), (18). Jobann Kunckel and Georg Ernst Stahl believed that the ore calamine contained a metal that alloys with copper to f o m brass, and even as late as 1735, the Swedish chemist, Georg Brandt, thought that calamine could not be reduced to a metal except in presence of copper (2), (19). In 1746, however, Andreas Sigismund Marggraf (20) heated a mixture of calamine and charcoal in a closed vessel in the absence of copper, and obtained a metal that differed from all others in hardness, specific gravity, and in its other properties (Z), (19). Ever since that time, zinc has been recognized as a distinct element. Some Swedish Metals In the eighteenth and nineteenth centuries Sweden far outstripped all other countries in the discovery of new elements. It is blessed with a rich supply of rare ores and, moreover, it had a long succession of brilliant chemists and mineralogists whose greatest delight was to investigate these curious minerals. In the century following the accidental discovery of phosphorus, three new metals, cobalt, nickel, and manganese, were discovered by Swedish chemists. Cobalt ' S
Georg Brandt ( 5 ) , the discoverer of cobalt, was born on June 26, 1694, a t Riddarhytta in the province of Vestmanland. He studied chemistry and mineralogy at the famous University of Upsala, and afterward rounded off his education, as so many other European chemists have done, by extended travel in foreign countries. He returned to Sweden well fitted to bear responsibility, and became connected with the Department of Mines, serving most successfully as assay-master of the Mint. Besides performing these duties for his government, he directed the chemical laboratory which had been established a t Stockholm. He was an honored member of the Stockholm Academy, and his many important papers were published in Swedish in the transactions of that society (6). Brandt's most important contribution to science was his discovery of the element cobalt. Its compounds had been used by Greek and Roman glassmakers to color the glass a beautiful deep blue, and by the Egyptians to tint their artificial gems. The fist mention of this metal is in the writings of Paracelsus (7). Berthelot thought, however, that metallic cobalt must have been prepared before the thirteenth century, for the alchemists understood how to roast and reduce ores. They did not, however, know how to refine the metals and distinguish between them (7).
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Ever since the sixteenth century a mineral of unknown composition had been uskd by European glassmakers. This mineral, when treated with acids, gave blue solutions just as copper ores do, but had the unusual property, not possessed by copper ores, of imparting a blue color to glass. Because of this seemingly mysterious behavior, the mineral was called "cobalt" from the German word Kobold, meaning subterranean gnome. These little, teasing earth sprites are frequently mentioned in Goethe's "Faust":
Salamander SOW gliiha Undene sich winden, Sylfihe verschwinden, Kobold sich miihen. We7 sie nicht kennte Die Elemente, Ihre Kraft, Und Eigenschaft, Ware kein Meister Uber die Geisler. (8)
Salamander shall kindle, Writhe nymph of the wave, In air sylph shall dwindle, And Kobold shall slave. Who dotb ignore The primal Four, Nor knows aright Their use and might, O'er spirits will he Ne'er master be. (8)
The Kobolds, according to an ancient German superstition, delighted in destroying the work of the miners, causing them endless trouble; and in mining towns the people used to pray in the churches for deliverance from the power of these malicious spirits (7). In 1735 Brandt examined the ore called "cobalt," and found that it contained a metal that gave it its property of producing a blue smalt. After separating this metal by fire assay, he *named it cobalt for the mineral from which he had extracted it. When Brandt died a t Stockholm on April 29, 1768, his death was mourned by the entire scientific world. He was one of the ablest chemists of his time (6). Nickel Alex Friedrich Cronstedt, the discoverer of nickel, was born on December 23, 1722, in the province of Sodermanland in Sweden (5). His father, a
lieutenant-general, gave him a good education, and he soon demonstrated his ability in physical science and mathematics. He rendered great service to his country as a metallurgist in the Bureau of Mimes, and his name will always be honored because of the brilliant manner in which he discovered the useful metal nickel (6) (24). The history of this metal is similar to that of cobalt. An alloy of nickel called packfong (or paktong) was used by the Chinese long before the metal was known in Europe (7), (23). In Germany a heavy, reddish brown ore, frequently found covered with green spots or stains, was used to color glass green; the miners called it Kupfernickel (21). Since Nickel, like Kobold, means deceptive little spirit, the word Kupfernickel may be trans-
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lated,false copper. Hierne, in a work on metals published in 1694, expressed a belief that Kupfernickel was a kind of cobalt or arsenic mixed with copper, but in this view there was only a germ of truth (7). When Kupfernickel (or niccolite, as it is called today) is dissolved in acids, green solutions are obtained which resemble those of copper, but Cronstedt, who began to study the ore in 1751, found such solutions to be very different from those of copper. I n one of his experiments he placed a piece of iron in the acid solution of the ore, expecting to see the copper deposit on it. To his great surprise, he was unable to secure a deposit of any kind, for, as is now well know& niccolite contains no copper (9). U ~ o ncalcinine the meen cnrstals which covered the surface of some weathered Kupfernickel, and reducing the calx, or oxide, by heating it with charcoal, Cronstedt obtained a white metal bearing no resemblance wbatever t o copper. After studying its physical, chemical, and magnetic properties, he announced in the Memoirs of the Stockholm Academy that . . he had discovered a new metal, difierent from all others, for wbich he proposed the name nickel (7), (21). He said, This salt or this vitriol, after B ~ T H A S AGEORGES R SAGE having been calcined, gives a col1740-1824 cothar or clear, gray residue which, when fused with three French analytical and mineralogical chemist of the phlogiston school. In parts of black flux, gives aregulus of 50 per quintal, hi^ his "Analyse in 1786, he gaveChimique," methods ofpublished testing and regu1us is yellowish on the outanalyzing coal, clay, water, and many side, but in the fractureit is silverminerals. colored with iridescent colors, and composed of little laminae, quite similar to those of bismuth. It is hard and brittle, only feebly attracted by the magnet, calcination changes i t to a black powder; these two properties come from the iron which has passed into the vitriol. This regulus dissolves in aqua fortis, aqua regia, and spirit of salt; it gives on dissolving a brilliant green color, and there precipitates a black powder which, when heated before the enamelers' blowpipe, gives signs of phlogiston and of the metallic part wbich it contains. . (7), (21).
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..
The slight magnetization observed by Cronstedt is now known to be a property of nickel itself. I n 1754 he roasted Kupfernickel with "black flux," placed some of the mixture in a crucible, and covered i t with a layer of common salt. Upon heating it to a very high temperature, he not only
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reduced the oxide to the metallic state, but melted the nickel. Kupfernickel, or niccolite, is now known to be an arsenide of nickel. Many chemists in Sweden and in other parts of the world immediately accepted Cronstedt's claim to the discovery of a new element, but Sage (22) and Monnet in France believed that his nickel was merely a mixture of cobalt, arsenic, iron, and copper (7). As a matter of fact, i t was somewhat contaminated with iron, cobalt, and arsenic; and therefore the great pioneer in analytical chemistry, Torbern Bergman, carried out an elaborate series of experiments by means of which he obtained nickel in a high " state of purity. The results he published in 1775 completely confirmed those of Cronstedt, for he showed that no combination of iron, arsenic, cobalt, and copper will duplicate the properties of nickel. Bergman's pupil, Arfvedson, defended these views in his thesis a t Upsala in 1775 (7). Even after this proof, some chemists were very conservative about accepting the new element. William Nicholson, in his "First Principles of Chemistry" published in 1796, gave .the following account of it: Chis metallic substance has not been applied to any use; and the chief attention of those chemists TORBERN R ~ ~ R O U A 1735-1784 N, who have examined i t has been Swedish chemist, mineralogist and directed to obtain i t in a state of editor. Author of the "Opuscula purity; which, however, has not physim et chemica." a six-volume yet been accomplished. . . . Nickel treatise. Among his students were Gahn, the discoverer of manganese; has been thought to be a modifiHjelrn, who isolated molybdenum; and cation or iron. . . . So long as no the d'Elhujar brothers, who discovered one is able to produce this metal tungsten. from pure iron or copper, and to explain in an intelligible way the process by which it can be generated, we must continue to regard it as a peculiar substance, possessing distinct properties. The general opinions of chemists concur in admitting the force of this reasoning (10). Cronstedt's fame does not rest alone on his discovery of nickel, for he made an excellent classi6cation of minerals which was translated into several languages. Berzelius said of him, "Cronstedt, the founder of the chemical system of mineralogy, a man who by his acuteness in that science rose so far above his age that he was never correctly understood by it, used the blowpipe to distinguish between minerals" (11). Ability to use
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this instrument skilfully and without fatigue and injury to health required, as Berzelius pointed out, an intensive training that few chemists care to undergo. Nevertheless, Cronstedt acquired such unusual control over i t that he could direct a candle-flame upon a sample no larger than the head of a pin and make it white-hot (11). Jagnaux states that Cronstedt and Rinmann operated a successful plant for distilling zinc, and that they "were as well versed in metallurgy as in mineralogy" (4). Cronstedt also discovered zeolite, the silicate which is so widely used for softening water, and wrote a paper on it in 1756. He died a t Stockholm on August 19, 1765. Manganese When Cronstedt died, the man who is conceded t o be the discoverer of manganese was exactly twenty years old. Johann Gottlieb Gahn was born a t Voxna, an iron-mining town in South Helsingland on August 19, 1745 (5). Left fatherless a t an early age and obliged to earn his living in the mines, he shared the joys and sorrows of the laborers and learned mining "on the lowest and wettest level" (17). He studied mineralogy under Bergman, and became a close observer, a profiJOHANN G O ~ I EGAHN B 1745-1818 cient analyst, and a brilliant mineralogist. Like Cronstedt, he was most an",w~i",~n,ch~~~;ernmi~~',"$~f expert in the use of the blowpipe - - and, turer of comer. sulfur. sulfuric acid. according to Berzelius, always carried ~ & l , ; ~ d ~ ~ ~ Discoverer ~ S e . of it with him. even on the shortest t r i ~ s . When Gahn demonstrated the presence of copper in certain kinds of paper by burning a quarter of a sheet, heating the ash with the blowpipe, and displaying a tiny speck of the red metal, the young Berzelius watched him with wonder and admiration (11). It was Gahn's discovery of phosphorus in bones that led Scheele to develop a means of isolating it from them (12). The ore, Braunstein, or pyrolnsite, was used by the alchemists for bleaching glass, and the Berlin glass and porcelain technologist, J. H. Pott, stated in 1740 that this mineral contained an earth differentfrom any then known (13). Cronstedt expressed the same view in his "System of Mineralogy." The mineral was also known a t that time by the confusing names "black magnesia" and "manganese." Bergman knew, however, that it was not a compound of the alkaline earth, magnesia, for he said, "The mineral called
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black magnesia is nothing other than the calx of a new metal, which must not be confounded with lime nor with magnesia alba." He failed, however, in all attempts to reduce the ore (13), (25), and finally turned the problem over to his friend, Scheele, who in 1774, after experimentingfor three years, presented his results to the Stockholm Academy in the form of a paper entitled, "Concerning Manganese and Its Properties." In this epochmaking dissertation he announced the existence of the gaseous elements, oxygen and chlorine, and paved the way for the discovery of the metals, barium and manganese. Scheele stated that the mineral known as "manganese" was the oxide of a metal different from any then known (26). Although Pott, Bergrnan, and Scheele all believed in the existence of the metal manganese none of them were able to isolate it. However, in 1774 Gahn (25) lined a crucible with moist charcoal dust, placed in the center a mixture of the pulverized pyrolusite and oil, and covered it with more of the charcoal dust. After luting another crucible to this, he heated them intensely for an hour and, upon opening the apparatus, he found in i t a button of metallic manganese weighing about a third as much as the ore from which he had isolated i t (13). For the accomplishment of this difficult reduction and for the isolation of this important metal, Gahn deserves high praise. In 1784 he was made assessor a t the College of Mines; he also served as deputy to the 1819 Diet, and was known politically as a Liberal (14). He was not only a brilliant chemisf and mineralogist and a conscientious public official, but also a highly successful business executive. He owned and managed mines and smelters, and inkoduced new industrial methods; and it was in his sulfuric acid plant that Berzelius discovered the element selenium. During the American Revolution, when large amounts of pure copper were needed for sheathing ships, Gahn's plant a t Stora Kopporberg was able to fill large rush orders (15). It is a curious fact that Assessor Gahn bore such a striking resemblance in features, gestures, and intellectual interests to Dr. William Hyde Wollaston, the English scientist who later discovered palladium and rhodium, that he was often called "the Wollaston of Stockholm" (IF). Berzelius once stated, in fact, that one "would take them for sons of the same father" (16). Thomas Thomson, who once visited Assessor Gahn a t his home in Fahlun, said that "his manners were the most simple, undected and pleasing of all the men of science" he had ever . beamed in his met, and that "benevolence and goodness of heart countenance" (15). Gahn, unfortunately, left most of his scientificwork unpublished, leaving only a few papers on the blowpipe, on a sensitive balance, and on economy in the operation of smelters. He died a t Stockholm on December 8,1818, a t the age of seventy-three years. In a biographical sketch in the "Annals of Philosophy," one may read this high tribute:
. .. .
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To sum up the whole, we may safely say that he wasalikeeminent as a oractical chemist and mechanic. as a oatriot in oublic. and a friend in *&ate, life, as presiding over the inierests of h e miner and of the farmer, and in fine as the guardian and overseer of the large family of his native poor.* It will not indeed be easy to find another whose talents have been a t once more brilliant and more useful, who has been more admiied and more loved by his country, than John Gottlieb Gahn (15). 'Assessor Gahn helped to establish the first poorhouse a t Fahlun.
Literature Cited "First Principles of Chemistry," 5th edition, Vol. 1, translated by (I) MENDEL~BEF, Kamensky and Greenaway, Longmans, Green & Co., London, 1891, preface, p. ix. (2) MELLOR,"Comprehensive Treatise on Inorganic and Theoretical Chemistry," Longmans, Green & Co., London, 1923,\'ol. 4, pp. 398405. Article on Zinc. (3) F a y , "History of Hindu Chemistry." 2ndedition. Vol. 1, Chuckervertty, Chatterjee and Co., Calcutta, 1904, pp. 157-8; 1st edition, Vol. 2, Bengal Chemical and Pharmaceutical Works. Calcutta, 1909, pp. 17. 19, and 22. (4) JAGNAUX,"Histoire de la Chimie," Vol. 2, Baudry e t Cie, Paris, 1891, pp. 209"Entstehung und Ausbreitung der Alchemie," Springer, 11; VON LIPPMANN, Berlin, 1919, pp. 591-600. "Biographisch-LiterarischesHandwdrterbuch zur Geschichte der (5) POGGENDORPP. exakten Wissenschaften," 5 vols., Verlag Chemie. Leipzig. 186.34926. Articles on Brandt, Cronstedt, and Gahn. (6) "Biographie Universelle, Anaenne et M@eme," 85 vols., Michaud Fr&res, Paris. 1811-1862. Biographical sketch of Brandt by Catteam. (7) JAGNAUX, "Histoire de la Chimie," ref. (a), Volr2, pp. 318-21; L. GMELIN, "Handbuch der theoretischen Chemie," ersten Bandes zweite Abtheilung, F. Varrentrapp, Frankfurt am Main, 1826, p. 1193; BRANDT,Act. Upsal., 1735, 33; WAITE, "Hermetic and Alchemical Writings of Paracelsus,"Vol. 1, Elliott and Co., London, 1894, p. 254. (8) GETHE. "Faust," part 1, lines 1273-1282. Translation from the "Harvard Classics," vol. 19, P. F. Collier and Son, New York, 1909-1910, p. 51. (9) FiiReEn, "Geschichtliche Entwicklung der Chemie," Springer, Berlin, 1921, pp. 6 3 4 . "First Prinaples of Chemistry." 3rd edition, C. G. and J. Robinson. (10) NICHOLSON, London. 1796, pp. 3635. (11) BERZELIUS,"Die Anwendung des LBtrohrs in der Chemie und Mineralogie," Zweite Adage, 1828; F. C. PHILLIPS,"Chemical Gemmi,'' 2nd edition, Chemical Publishing Co., Easton, Pa., 1915, p. 103; B E R Z E L ~ S "Om , BI&rorets Anvilndande i Kemien och Mineralogien," Nordstrtim, Stockholm, 1820, pp. 1-8. "History of Chemistry;' Vol. 2. Colburn and Bentley. London, 1831, (12) THOMSON. p. 243. "Histoire de la Chimie," ref. (4). Vol. 2, pp. 3 1 5 4 ; L. GMELIN, (13) JAGNAUX, "Handbuch der theoretischen Chemie," ersten Bandes zweite Abtheilung, ref. (7). p. 882. See also HIELM, 'Versuche aus dem Braunsteine den Braunsteinkonig (Magnesium) zu erhalten," Crell's Ann., 7, 158-68; 446-57 (1787). (14) HOEFER,"Nouvelle Biographie G6n&aIe," Didot Frsres, Paris, 1866. Biagraphical sketch of Gahn by Guyot de Fke.
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"Biographical Account of Assessor John Gottlieh Gahn." Annals of Philos., New Series. 8, 1-11 (July, 1824). S~DERBAWM, "Jac. Berzelius Bref," Vol. 1, part 3, Almqvist and Wiksells, Upsala, 1912-1914, p. 242; EMILIE W ~ H L E R - G O T ~ N G "AUS E N , Berzelius's Tagebuch wiihrend seines Aufenthaltes in London im Sommer 1812," Z. angnu. Chem., 18, 1946-8 (Dec., 1905). HOOVER,radio address of acceptance of the Saunders Medal. BERGMAN, "Opuscula Physica et Chemica," Vol. 2, Miilleriano, Lipsiae, 1792, pp. 309-14. KOPP, "Geschichte der Chemie," part 4, F. Vieweg und Sohn, Braunschweig, 1847, pp. 113-20. E. F. SMITH,"Forgotten Chemists," J. CHEM.EDUC.,3, 31-2 (Jan., 1926). BERGMAN, "Opuscula Physica e t Cbemica," ref. (la), Vol. 2, pp. 2 3 1 4 ; CRONSTEDT, Abhandl. der Schwed. Akad. der Wiss., 1751, 293 and 1754,38. SAGE, "MCmoires de Chimie," Imprimerie Royale,. Paris, 1773, pp. 116-26. "Examen de la Mine de Cobalt d'un gris rougeatre nommee Kupfernickel." BALDWIN."The Story of Nickel. Part 1. How 'Old Nick's' Gnomes Were Outwitted." J. CHEM.EDUC.,8, 1749-50 (Sept., 1931). KOPP, "Geschichte der Chemie," ref. (19). part 4, pp. 157-9. BERGMAN, "Opuscula Physica e t Chemica," ref. (18). Vol. 2, pp. 2 0 1 4 . SCHEELE, "Sammtliche physische und chemische Werke," translated into German by Hermbstiidt, 2nd edition, Vol. 2, Rottmann. Berlin. 1793, pp. 33-90
