THE DISCOVERY OF THE ELEMENTS. 11. ELEMENTS KNOWN TO THE ALCHEMISTS* MARYELVIRA WEEKS. THE UNIVERSITYOF KANSAS. LAWRENCE, KANSAS
The alchemists never succeeded in making gold f r m base metals, yet their experiments, recorded under a mystical and intentionally obscure terminology, gradually revealed metallic arsenic, antimony, and bismuth. Finally, i n the latter part of the seventeenth century, the pale light of phosphorus began to illumine the dark secrets of alchemy and to disclose thesteady advance of d e n tZfic chemistry.
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" . . . .Surely to alchemy this right i s due, that it may be compared to the husbandman whereof Aesop makes the fable; that, when he died, told his sons that he had left unto them gold buried underground i n his vineyard; and they digged over all the ground, and gold they found none; but by reason of their'stirring and digging-the mould about the roots of their vines, they had a great vintage the year following: so assuredly the search and stir to make gold hath brought to light a great number of good and fruitful inventions and experiments. . ." ( I ) The part played in ancient civilizations by gold, silver, copper, iron, lead, tin, mercury, carbon, and sulfur has already been shown. Certain
other elements, although their lineage is not quite so ancient, havenevertheless had a history that extends far back through the centuries. In this group may be mentioned arsenic, antimony, bismuth, and phosphorus; and, 'Illustrations by F.B. Dains, The University of Kansas, Lawrence, Kansas. 11
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strangely enough, these four simple substances have so many characteristics in common that they constitute one of the groups in the system of classification now universally usedby chemists. Their early history is so shrouded in uncertainty that only in the case of phosphorus is it possible ro assign the honor of discovery de6nitely to any person.
Arsenic Although the Greeks and Romans used a substance which they called " arsenic," this was not the metal itself. The socalled "arsenic" of the ancients consisted of the poisonous sultides, orpiment, a n d sandarac, mined with heavy loss of life by slave labor (2). No one knows who first isolated the metal, but this honor is sometimes accredited to Albert the Great (Albertus Magnus, ALBERTUS MAGNUS. 1193-1280 1193-1280), who obGerman Dominican scholar and alchemist who intained it by heating orpiterpreted Aristotle to the Latin races. Author of "De Mincralibus." He also contributed to mement with soap (3). chanics, geography, and biology. Paracelsus (I5), . . the eccentric and boasffd medical alchemist of the sixteenth century, mentioned a process for obtainmg metallic arsenic, "white like silver," by heating the so-called "arsenic" of the ancients with egg shells (18). Berthelot believed, however, that metallic arsenic was known much earlier than this, for it is easily reduced from its ores. Since it sublimes easily, and readily forms soft alloys with other metals, and since the arsenic sulfide, realgar, looks
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very much like the corresponding mercury ore, cinnabar, the alchemists regarded arsenic as a k i d of quicksilver. The Pseudo-Democritus gave the following method of reducing the ore: " F i xthe mercury obtained from arsenic (sulfide) or from sandarac, throw it on to copper and iron treated with sulfur, and the metal will become white" (31, (17). In 1649 Schroeder published a pharmacopeia in which he gave two methods of obtaining metallic arsenic: (1) by decomposing orpiment, arsenious sulfide, with lime and (2) by reducine
searches of J. F. Henckel (1725), Georg Brandt (1733), J. Brouall (1744), and Monnet (1774) (16). Brouall also observed that it, like sulfur, is present, in small amounts a t least, in most ores (3). Antimony
, C
Antimony, like arsenic, was known to the ancients, but perhaps only in the form of its sulfide, which Oriental women of leisure used to use to darken and beautify their eyebrows ( 4 ) . Berthelot's belief that metallic antimony was known to the ancient Chaldeans was based on his analysis of a most unusual vase that had been brought to the Louvre from the ruins of TeUo, and which he found to consist of pure metallic antimony, containing only a trace' of iron (5), (19). He also quoted the following passage from Dioscorides: "One roasts this ore (antimonious sulfide) by placing it on charcoal and heating to incandescence; if one continues the roasting, i t changes into l e a d (5). Pliny issued thesame From Pelerr' "Aur p h a r r n o z ~ i ~ r i r rVorreil h~~ in Bild und Wort'' warning in his description SBVENTEENTH-CENTURY ALCHEMISTICSYMBOL FOR of the preparation of antiANTIMONY
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From LoWoN'r "Pour Thourond Yaurr of Pharnary"
FRONTISPIECE =OM JOHNSCHROEDER'S PHARMACOPEIA, 1646
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mony medicinals, when he said: "But the main thing of all is to observe such a degree of nicety in heating it, as not to let it become lead" (4). Hence it is evident that the Romans, like the Chaldeans, knew how to obtain antimony; but, since they did not have adequate methods of distinguishing between metals, they applied the indefinite term "lead" to all those that were soft, easily fusible, and black. Probably the earliest book about this metal is the curious "Triumphal Chariot of Antimony" by Basil Valentine, whom some of the early historians of chemistry regarded as the discoverer of the element. It is now known that Valentine was a mythical character evolved from the imapination of the real author, Johann Tholden of Hesse, a city councilor in Franckenharsen, Thuringia, who operated a salt-works there in the early part of the seventeenth century. He wrote a number of chemical books in German in a literary style resembling that of Paracelsus, and claimed that he had translated most of them from the original Latin manuscripts of a fifteenth-century Benedictine monk, Basilius Valentinus (6). The writings of the alchemists abound in flowery references to antimony, for its compounds played a large part in the search for the elixir of life, or universal panacea. The first really scientific treatise on the element was XICOLAS LBMERY,M.D., 1645-1715 that of Nicolas L h e t y (1645-1715), French Author of entitled "Trait6 de l'antbnoine, con- d, chimie; one of the textbooks that tenant ~ ' &imique ~ de ~ ce Scheele ~ studied,l and of ~a treatise ~on antimony. min6ral" (3). Bismuth The ancient peoples failed to distinguish bismuth from lead and tin. Early in the sixteenth century, Georgius Agricola wrote a famous treatise called "Bermannus," in which he mentioned that bismuth was well known in Germany. In believing i t to be a specific metal, different from all others, he was far in advance of his age, for the idea that bismuth was a kind of lead persisted even into the eighteenth century (7). The miners, in accordance with the prevalent beliefs that there were three kinds of lead (ordinary lead, tin, and bismuth), and that bismuth had progressed farthest in its transmutation into silver, called it "tectum argent? or
~
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"unfinished silver." When they stmck a vein of bismuth they said naTvely and sadly, "Alas, we have come too soon" (7). Even as late as 1713 the Proceedings of the Frelach Academy contained the statement that bismuth is composed of a mineral, crude sulfur, mercury, arsenic, and earth; and thepharmacopeias of that time contained recipes for makimg it (7). Lemery, for example, described the following method which he said was used in the English tin mines: "The workmen," said he, "mix this tin with equal parts of tartar and saltpetre. This mixture they throw by degrees into crucibles made red hot in a large fire. When this is melted, they pour it into greased iron mortars and let it cool. Afterward they separate the regulus a t the bottom from the scoriae and wash it well. This is the tin-glass which may he called the regulus of tin" (13). The French chemist, Hellot, noticed, however, That the tin smelters in Cornwall added natural bismuth, instead of the ingredients recommended in the pharmacopeias, to make the tin hard and brilliant, and in 1737 he obtained by fire assay of a cobalt ore a button of the metal (7). Claude Joseph Geoffroy (Geoffroy the Younger) published in 1753his famous treatise called "The Chemical Analysis of Bismuth." Although death cut short his researches, he showed clearly that it is an individual metal, distinct from lead, and described its most striking properties (7). Phosphorus In the seventeenth cenhuy there lived in Hamburg a merchant by the name of Hennig Brand (or Brandt), whg was apparently the first man ever to discover an element. Of course, gold and lead and the other metals and non-metals used in ancient civilizations must have been discovered by somebody, but these great contributors to human knowledge are as unknown today as is that greatest of all inventorsthe man who made the first wheel. Brand was a soldier in his youth, and it is said that later he became "an uncouth physician who knew not a word of Latin" (8). In spite of this deficiency he married a wealthy wife, but after her death he lost the inherited money. In an attempt to regain his lost financial standing, he was lured by the spell of alchemy to search for the King of Metals. No one knows what led this zealous alchemist to hope that in human urine he might find a liquid capable of converting silver into gold, but it is well known that his queer experiments made in 1669 produced results that were both startling and strangely beautiful. Small wonder that he was delighted with the white, waxy substance that glowed so charmingly in his dark laboratory. The method of obtaining this light-giving element, which is now called phosphorus, Brand kept secret, but the news of the amazing discovery soon spread throughout Germany (9). There lived at that time a famous chemist, Johann Kunckel(1630-1702),
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German chemist, pharmacist, and glass technologist. Independent discoverer of phosphorus. Caullselor of Metals under King Charles XI of Sweden. (The portrait reproduced herewith is the frontispiece of Kunckel's "Ars Vitraria Experimentalis," published during his lifetime, in 1679.)
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a son of an alchemist in the court of the Duke of Holstein (10). The younger Kunckel studied pharmacy, glass-making, and assaying; worked in the Dresden laboratoty of John ~ e o r i e11, Elector of Saxony; taught chemistry in the famous medical school a t Wittenberg; and later managed the glass-works in Berlin belonging to Frederick William, the Elector of Brandenburg. His last years were spent in the service of King Charles XI of Sweden, who conferred on him the titles, Baron von Lijwenstern and Connselor of Metals (10). One day Kunckel proudly exhibited to a friend in Hamburg, much as a modem chemist might show a specimen of hafnium or i l l i n i u m a match. To his great surprise, the friend had not only seen matches before, but offered to take Kunckel to the home of the medical alchemist, Dr. Brand, to see a still more remarkable substance that shines spontaneously in the dark. Brand, they found, had given away his entire supply, hut he took Kunckel to the home of a friend to see the wondrous element. Kunckel, in the heat of excitement, wrote immediately to his friend, Dr. Johann Daniel Krafft of Dresden. The latter, however, proved to be a false friend, for, without replying to Kunckel's letter, he went immediately to Hamburg and bought the secret from Brand for two hundred thalers. Just as the transaction was being made, Knnckel arrived on the scene. All his attempts to learn the secret process failed, but he did find out that
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the new luminous substance, which had come to be known as phosphorus, had been obtained from urine (8). Kunckel then began experimenting with this fluid, and was finally successful. Like Brand, he refused to reveal the method, giving as his reason the fear that dangerous accidents with phosphorus might become frequent. According to Homberg, Kunckel's process was essentially as follows: Fresh urine was evaporated nearly to dryness, after which the black residue was allowed to putrefy in a cellar for several months. This material was heated, gently a t first and then strongly, with twice its weight of sand, in a retort leading to a receiver containing water. After the volatile and oily constituents had distilled over, the phosphorus began to settle out in the receiver as a white, waxy solid. This was the part of the process which Kunckel thought too dangerous to reveal to the public. To prevent fires and explosions, it was necessary to remove the flame as soon as the phosphorus began to appear, and to keep the receiver closed until it became cold ( 8 ) . Kunckel not only prepared phosphorus, but also cast it in molds to obtain the stick phosphorus now familiar to all chemistry students. He also introduced its use as a medicinal, and his famous book on the subject bears the curious title: "Treatise of English chemist and physicist the Phosphorus Mirabilis, and Its famous for his researches on gases, his air numo. his earl" ex~erimentson the Wonderful Shining Pills" (10). It is m&han&l orinid o i heat, and .his pleasant to know that his discovery of independent discovery of phosphorus. One of the founders of quantitative the element was not without reward, analysis. for Duke Johann Friedrich of Hanover paid him an annual pension for the rest of his life (9). According to Thomas Thomson (ll),William Homberg purchased Kunckel's secret of making phosphorus by giving in exchange the ingenious barometer invented by Otto von Guericke, in which a little man comes to the door of his house in dry weather and discreetly retires within as soon as the air becomes moist. It would be unfair to conclude this brief account of the discovery of phosphorus without mentioning that Robert Boyle, the illustrious English pioneer in pneumatic cliemistry, also discovered it independently. He prepared it by a method somewhat resembling that of Kunckel, but, as
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Boylehimself said, without any previous knowledge of that process. Boyle was a man of such high integrity that one cannot doubt the truth of his statement. His assistant, Godfrey Hanckwitz, made phosphorus on quite a large scale, and exported it to Europe (12). One of his advertisements reads as follows: "Ambrose Godfrey Hanckwitz, chemist in London, Southampton Street, Covent Garden, continues faithfully to prepare all sorts of remedies, chemical and galenical . . . . For the information of the curious, he is the only one in London who makes inflammable phosphorus, black phosphorus, and that made with acid, oil, and other varieties. All unadulterated. Eyery description of good drugs he sells, wholesale and retail. Solid phosphorus, wholesale, 50 s. an ounce, and retail, £3 sterling, the ounce" (14). Until 1737 the method of manufacturing phosphorus remained a secret, but in that year a stranger in Paris offered to sell the secret process to the Academy of Sciences. After accepting the offer, the French government appointed John Hellot chairman of a committee to study the process, and his detailed report, published in the Memoirs of the Academy for 1737, made the process accessible to all chemists (12). However, phosphorus is no longer prepared by the unpleasant method described above. In 1774 the Swedish chemist, Johann Gottlieb Gahn, found that i t is an important constituent of bones, and in the following year Scheele succeeded in isolating i t from them (8). It really is strange that phosphorus was discovered so early in the history of chemistry, for the reactions involved in Brand's method are rather complex, and. even today this element is not isolated with ease.
Literature Cited FRANCIS, "The Advancement of Learning," edited by Wm. A. Wright, ( 1 ) BACON, 3rd edition, Clarendon Press, Oxford, 1885, p. 36.
, History," translated by Bostock and Riley, Geo. Bell and ( 2 ) P L I ~"Natural Sons. London, 1856, Book XXXIII. Chap. 22; Book XXXIV, Chap. 55; JAGNAUX. "Histoire de la Chimie." Vol. 1, Baudry e t Cie, Paris. 1891, pp. 656-8. (3) JAGNAWX, "Histoire de la Chimie," ref. ( 2 ) ,Vol. 1,pp. 656-8. (4) PLNY, "Natural History," ref. (2). Book XXXIII, Chap. 34; RAY, "History of Hindu Chemistry," 1st edition, Vol. 2, Bengal Chemical and Pharmaceutical Works. Calcutta, 1909, p. 54. ( 5 ) JAGNAUX, "Histoire de la Chimie," ref. (Z), Vol. 2, p. 325; C m c Yu WANG, "Antimony. Its History, Chemistry. Mineralogy, Geology, Metallurgy, Uses. Preoarations. Analvsis. . . Production. and Valuation." Chas. Griffin and Ca.. London, 1909, pp. 1-5. (.6.) STILLMAN."The Stow of Early Chemistry." D. Aooleton'and Co.. New York. 1924, pp. 372-6; T. L. D~v~s,"~nestion;forthe &dent of Elementary hem: istry," J. CHEM.Eouc., 7, 11414 (May, 1930). (7) JAGNAIJX, "Histoire de la Chimie." ref. ( 2 ) , Vol. 2,pp. 331-2; KOPP,"Clesehichte der Chemie," part 4, F. Vieweg und S o h , Braunschweig, 1847, pp. 110-2. , (8) JAGNAUX,"Histoire de la Chimie." ref. (2).Vol. 1, pp. 634-7;W o o r r o ~"Chronid e s of Pharmacy," Vol. 1, Macmillan and Co., London, 1910, pp. 360-7; Kmc-
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MWENSTERN, "ViillstBudiges Laboratorium Chymicum." vierte Adage. Riidigerschen Buchhandlung, Berlin, 1767, pp. 5 9 5 4 9 . POGOENDORPP. "Biographisch-Lite~arisches Handw6rterbuch zur Geschichte der exakten Wisenschaften," 5 vols., Verlag Chemie, Leipzig, 1865-1926. Article on Brand. THOMSON, "History of Chemistry," Vol. 1, Colbum and Bentley, London. 1830, pp. 233-5; T . L. DAVIS, "Kunckel and the Early History of Phosphorus," J. CHEM.EDUC.,4, 1105--13 (Sept., 1927). TnomsoN, "History of Chemistry,"ref. (10). Vol. 1, p. 240; CRELL,"Neues chem. Archiv.,"Vol. 1, J. G. Miiller, Leipzig, 1784, pp. 77-8. THOMSON, "History of Chemistry," ref. (10). Vol. 1, pp. 2 8 M . WOOITON,"Chronicles of Pharmacy," ref. (8). Vol. 1, p. 387; KOPF, "Geschichte der Chemie," ref. (7), part 4, p. 111. LA WALL."Four Thousand Years of Pharmacy." J. B. Lippincott Ca., Phila.. delphia, 1927, p. 336. T. L. DAVIS,"Boerhaave's Account of Paracelsus and van Helmont," J. CHEM. Enuc., 5, 671-81 (June, 1928). KOPP, "Geschichte der Chemie," ref. j7), part 4, p. 92. BERTRELOT, "La Chimie au Moyen Age," Vol. 1, Imprimerie Nationale, Paris, 1893, p. 263. WAITE, "The Hermetic and Alchemical Writings of Paracelsus," Vol. 1, Elliott and Co., London, 1894, p. 58. VON L I P ~ N N"Entstehung , und Ausbreitnng der Alchemie." Springer, Berlin, 1919, pp. 62WO. KEL YON