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BOOK IX.
409
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Then the stannum runs out of the furnace into the forehearth ; this is an alloy
of lead and silver. From the silver-lead alloy they first skim off the slags, not rarely white, as some pyrites49 are, and afterward they skim off the cakes of pyrites, if there are any. In these cakes there is usually some copper ; but since there is usually but a very small quantity, and as the forest lines—first, that of the metal, and second, that of zinc ore, for the latter was known and used to
make brass by cementation with copper and to yield oxides by sublimation for medicinal purposes, nearly 2,000 years before the metal became generally known and used in Europe. There is some reason to believe that metallic zinc was known to the Ancients, for
bracelets made of it, found in the ruins of Cameros (prior to 500 B.c.), may have been of that age (Raoul Jagnaux, Traité de Chimie Générale, 1887, π, 385) ; and further, a passage in Strabo (63 b.c.—24 a.D.) is of much interest. He states : (xin, 1, 56) " There is found at " Andeira a stone which when burnt becomes iron. It is then put into a furnace, together " with some kind of earth, when it distils a mock silver (pseudargyrum), or with the addition " of copper it becomes the compound called orichalcum. There is found a mock silver near " Tismolu also." (Hamilton's Trans., n, p. 381). About the Christian era the terms orichalcum or aurichalcum undoubtedly refer to brass, but whether these terms as used by earlier Greek writers do not refer to bronze only, is a matter of considerable doubt. Beyond these slight references we are without information until the 16th Century. If the metal was known to the Ancients it must have been locally, for by its greater adaptability to brassmaking it would probably have supplanted the crude melting of copper with zinc minerals. It appears that the metal may have been known in the Far East prior to such knowledge
in Europe ; metallic zinc was imported in considerable quantities from the East as early as the 16th and 17th centuries under such terms as tuteneque, tuttanego, calaëm, and spiauter—the latter, of course, being the progenitor of our term spelter. The localities of Eastern production have never been adequately investigated. W. Hommel (Engineering and Mining Journal, June 15, 1912) gives a very satisfactory review of the Eastern literature upon the subject, and considers that the origin of manufacture was in India, although the most of the 16th and 17th Century product came from China. The earliest certain description seems to be some recipes for manufacture quoted by Praphulla Chandra Ray (A History of Hindu Chemistry, London, 1902, p. 39) dating from the nth to the 14th Centuries. There does not appear to be any satisfactory description of the Chinese method until that of Sir George Staunton (Journal Asiatique, Paris, 1835, p. 141.) We may add that spelter was produced in India by crude distillation of calamine in clay pots in the early part of the 19th Century (Brooke, Jour. Asiatic Soc. of Bengal, vol. xix, 1850, p. 212), and the remains of such smelting in Rajputana are supposed to be very ancient. The discovery of zinc in Europe seems to have been quite independent of the East,
but precisely where and when is clouded with much uncertainty. The marchasita aurea of Albertus Magnus has been called upon to serve as metallic zinc, but such belief requires a hypothesis based upon a great deal of assumption. Further, the statement is frequently made that zinc is mentioned in Basil Valentine's Triumphant Chariot of Antimony (the only one of the works attributed to this author which may date prior to the 17th Century), but we have been unable to find any such reference. The first certain mention of metallic zinc is generally accredited to Paracelsus (1493-1541), who states (Liber Mineralium 11.) : " More" over there is another metal generally unknown called zinken. It is of peculiar nature and " origin ; many other metals adulterate it. It can be melted, for it is generated from three " fluid principles ; it is not malleable. Its colour is different from other metals and does not " resemble others in its growth. Its ultimate matter (ultima materia) is not to me yet fully " known. It admits of no mixture and does not permit of the fabricationes of other metals. " It stands alone entirely to itself." We do not believe that this book was published until after Agricola's works. Agricola introduced the following statements into his revised edition of Bermannus (p. 431), published in 1558 : " It (a variety of pyrites) is almost the colour " of galena, but of entirely different components. From it there is made gold and silver, and " a great quantity is dug in Reichenstein, which is in Silesia, as was recently reported to me. " Much more is found at Raurici, which they call zincum, which species differs from pyrites, " for the latter contains more silver than gold, the former only gold or hardly any silver." In De Natura Fossilium (p. 368) : " For this cadmia is put, in the same way as quicksilver, " in a suitable vessel so that the heat of the fire will cause it to sublime, and from it is made " a black or brown or grey body which the Alchemists call cadmia sublimata. This " possesses corrosive properties to the highest degree. Cognate with this cadmia and pyrites " is a compound which the Noricans and Rhetians call zincum." We leave it to readers to decide how near this comes to metallic zinc ; in any event, he apparently did not |
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*· " . . . non raro, ut nonnulli pyritae sunt, candida . . . " This i*
apparently the unknown substance mentioned above. |
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