TEE EVOLUTION OF CEEMICAL TRUTE. 817 



Zosimus, the experimenter, the historian and biographer of Plato, 

 Olympiadorus, and Stephanus, authors of important memoirs on 

 the art of making gold. For that purpose they employed, accord- 

 ing to the manuscripts, a projecting powder endowed with the 

 mysterious power of impregnating bodies. This powder was pre- 

 pared in the Thebaid, at places which, according to Agatharcides, 

 were centers of metallurgical enterprises. 



In the ninth century all the documents are found in the hands 

 of the Arabs, who became the depositories and continuers of 

 Grecian science. Mussulman civilization has handed down to us 

 the history of the mythic alchemists, their mysterious formulas, 

 and the practices which they adopted for blanching and yellowing 

 metals — that is, for changing them into silver and gold. In their 

 conceptions of matter, the Arabs of Spain and Syria followed in 

 part the philosophical systems of pagan Greece; and their au- 

 thors freely quoted Aristotle, Heraclitus, Xenocrates, Diogenes, 

 and Democritus. The story of their doctrines and brilliant dis- 

 coveries is told in all histories of chemistry. 



M. Berthelot's detailed review of the positive facts which 

 alchemy received from antiquity makes it manifest that Egypt 

 left an inestimable treasure to the world. The priests of Thebes 

 and Memphis made great advances in the knowledge of the art of 

 extracting metals, of forming alloys, and of making vessels and 

 tools out of them. They distinguished crude gold from refined 

 gold, and could work that metal up into a variety of articles. 

 They fed the hope that they might be able to obtain it by color- 

 ing asemon, or silver, yellow. Of the latter metal they made 

 money, the value of which was guaranteed by an impressed im- 

 age. They extracted gold and silver from electrum, a mineral 

 containing both substances, but which presented to their eyes the 

 appearance of a metal like them. This was what led them to the 

 notion of transmutation. 



The Egyptians designated as cTiesbet several kinds of blue 

 or green sapphires colored with cobalt or copper. They made in- 

 crustations, amulets, necklaces, and various ornaments of them. 

 They succeeded in compounding an artificial chesbet resembling 

 the natural stone. A fact worthy of remark in the matter is, 

 that this was done by " the assimilation of a colored substance, a 

 precious stone, an enamel, a vitrified color, with metals." This 

 assimilation suggested the new idea of dyeing ; " for the imitation 

 of the sapphire rests on the coloring of a large mass, colorless 

 by itself, but constituting the vitrifiable basis, which we dye by 

 the aid of a small quantity of coloring matter. With enamels 

 and colored glasses thus prepared, the natural precious stones 

 were reproduced ; they were covered with figures, with objects of 

 earth or stone, and were incrusted with metallic objects." 



vol. xxxyn. — 59 



