ZINC 819 upon the inner furnace walls when zincose ores are smelted. Sometimes the cadmia of Pliny appears to mean either natural calamine or furnace calamine. This confusion is found in other ancient writers, and is not unnatural, considering the stony appearance of the latter product, and the circumstance that both were found to yield with copper the same alloy. Festus (writing at some time between about A. D. 100 and 400) says : Cadmia, terra quce in CES conjicitur, utfiat orichaleum. Ambrose, bishop of Milan, writes similarly in the 4th century. Beckmann cites Aristotle and Stra- bo concerning an ore of this nature, used for making brass, and Dioscorides and Galen as to the artificial product, which in their time was used medicinally, particularly in ophthal- mic diseases. The term tutia (whence our tutty, as from cadmia our calamine), used in the llth century by Avicenna, was similarly applied by the Greeks and Arabians to both the artificial and natural compounds rich in zincic oxide. Zosimus (a writer of the 5th century, as Beckmann supposes) prescribes the smelting of Cyprus copper and strewing of pounded tutia over it, to make brass ; and the alchemist Hermes taught the use of tutia (of which he speaks as an artificial product from copper-smelting furnaces) in th trans- mutation of metals, for giving a gold color to copper. Yet in Germany the nature of fur- nace calamine seems to have been unknown or forgotten, until in the 16th century Eras- mus Ebener showed that the vast quantities of it which had accumulated at the Kammels- berg furnaces might be used instead of native calamine in the manufacture of brass. The general ignorance of metallic zinc, coupled with such ancient and general use of its oxide and alloys, was due to its volatility and oxi- dability. It was at Goslar, near the Rammels- berg, in the Hartz, that the Dominican monk Albertus Magnus, in the 13th century, obtained the metal, which he called marchasita aurea. Paracelsus, who died in 1541, first described it distinctly, and called it zinc (probably from zinlce, a nail, in allusion to its crystalline frac- ture). He knew of it only as produced in Oa- rinthia. Agricola (about 1550) speaks of the Goslar zinc as liquor candidus, or, in German, conterfey ; and Fabricius, who died in 1571, conjectures that stibium is what the miners call cincum, which can be melted but not ham- mered. The alchemists, attracted by its prop- erty of giving a golden color to copper, prob- ably expected great things from it, and sought to keep its nature secret. As late as 1617 it appears to have been an accidental product only of the Goslar furnaces, and in great re- quest among the alchemists. Lohneysen says a metal called zinc or conterfeht, resembling tin, but harder and less malleable, collected in crevices under the melting furnace, where the stones were not well plastered. A few ounces, or at most two pounds, could be ob- tained at one time. Henkel is named by Beck- mann as the first who intentionally manufac- tured zinc from calamine. This was prob- ably in 1721. By 1737 the manufacture was in successful operation in England, where it was invented by Dr. Isaac Lawson, a Scotch- man. A. von Swab, of the Swedish council of mines, distilled zinc from calamine in 1742. Works were established at Bristol in 1743 by John Champion, who took out a patent in 1758 for the use of blende. His process was the destillatio per de&censum, described below. Calamine brass had been made in Surrey a century before. The production of zinc in the East Indies is of still earlier date. As "Indian tin," or speautre (whence "spelter"), it was imported into Europe by the Dutch, who, it is said, captured a cargo of it from the Portuguese before 1640. It is vaguely referred to as coming from China, Bengal, Malacca, and the Malabar coast. According to Kaynal, the Dutch East India company purchased an- nually in the latter part of the 18th century, at Palembang, 1,500,000 Ibs. of zinc. The process of extracting it from its ores is said to have been brought to Europe by an Englishman, who went to India to discover the secret. The first zinc produced in the United States was made about 1838, at the United States arsenal in Washington, from the red oxide of New Jersey, for the brass designed for standard weights and measures ordered by congress. The pro- cess proved so expensive as to discourage for a long time the idea of treating this ore. The regular manufacture was first undertaken at the works of the New Jersey zinc company in 1850. The Belgian plan, first adopted, failed by reason of the chemical action of the ore upon the retorts. The oxide of iron in the franklinite, associated with the red zinc ores, was particularly injurious, forming a fusible silicate with the silex of the clay. The Silesian plan, tried in 1856 by Matthiessen and Hegeler at the works of the Lehigh company, also proved a failure. Samuel Wetherill of Beth- lehem, Pa., attempted to produce spelter by treating zinc ores in open furnaces, the oxi- dized vapors being drawn through incandescent anthracite to reduce the oxide. Joseph W T har- ton is said to have experimented on a some- what similar plan at Camden, N. J., but the idea cannot be said to have proved practicable, though Mr. Wetherill, who obtained a patent for his process, made a few tons of zinc. He subsequently recommenced the business, using upright retorts, and succeeded in obtaining materials and devising a mixture sufficiently refractory for his purpose. This important desideratum being secured, the Lehigh zinc company, of which Mr. Wharton was manager, returned to the Belgian furnace, importing a metallurgist and skilled workmen, and finally in 1860 constructed works at Bethlehem, where it still carries on the process. Meanwhile the manufacture of zinc white, which involves le diflaculty and loss, and for which the purity of the Pennsylvania and New Jersey ores and
