u6 THE HISTORY OF CHEMISTRY, 



treats on the docimaftic art. In this are de- 



fcribcd the docimaftic furnaces, ovens, dilh- 



es, cupels made of burnt bones or aflies, alfo 



Ihades, melting furnaces, crucibles, iron hooks, 



fcalcs, buckets for \vafliing the ore, and various 



kinds of weights: It teaches the method like- 



wife of afcertaining how much gold, filver, 



quickfilver, lead, copper, iron, tin, or bifmuth, is 



contained in every ore; and in what manner 



gold or lilver coin may be examined on the Ly- 



dian itone, by proof needles; the invert iga- 



tion of the qualities of gold by the nitrous acid, 



quartatkm, and the increafe of weight from the 



filver rcfiduum; and many other things. We 



meet in this book with almoft every thing now 



in life in the docimuftic art, and the fame kinds 



of procefles ; except that the inilruments and 



methods of operating are become more fimplc 



and accurate. The lead of Villachia is laid to 



contain no lilver. In the eighth book we have 



an account of the feparating ores from the rock, 



of calcining and pounding them; and alfo a par- 



ticular method of purifying them through a 



iievc, or by waflimg in fome other manner. The 



ninth enumerates the various forts of furnaces, 



with their bellows, and the leveial methods by 



which, from the greater portions of minerals, 



$;old, lilver, lead, copper, iron, tin, and bifmuth, 



may be extracted by the means of fire. The 



tc:;:h relates in \vh:it way gold and i'ilvr may 



