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BOOK V. 



than this, because Nature bestows quantity in place of quality ; such ore 

 is mixed with all kinds of earth and stone compounds, except the various 

 kinds of rudis silver ; especially with pyrites, cadmia metallica fossilis, galena, 

 stibium, and others. 



that not only copper but also silver may be smelted from it, and indeed occasionally both 

 copper and silver together. Sometimes, as is the case with pyrites, it is entirely devoid 

 of metal. It is frequently found in copper mines, but more frequently still in silver mines. 

 And there are likewise veins of cadmia itself. . . . There are several species of the 

 cadmia fossilis just as there were of cadmia fornacum. For one kind has the form of grapes 

 and another of broken tiles, a third seems to consist of layers. But the cadmia fossilis 

 has much stronger properties than that which is produced in the furnaces. Indeed, it often 

 possesses such highly corrosive power that it corrodes the hands and feet of the miners. 

 It, therefore, differs from pyrites in colour and properties. For pyrites, if it does not 

 contain vitriol, is generally either of a gold or silver colour, rarely of anj' other. Cadmia 

 is either black or brown or grey, or else reddish like copper when melted in the furnace. 

 . . . . For this cadmia is put in a suitable vessel, in the same way as quicksilver, so 

 that the heat of the fire will cause it to sublimate, and from it is made a black or brown or 

 grey body which the Alchemists call "sublimated cadmia" (cadmiam sublimatam). This 

 possesses corrosive properties of the highest degree. Cognate with cadmia and pyrites 

 is a compound which the Noricians and Rhetians call zincum. This contains gold and 

 silver, and is either red or white. It is likewise found in the Sudetian mountains, and is 

 devoid of those metals. . . . With this cadmia is naturally related mineral spodos, 

 known to the Moor Serapion, but unknown to the Greeks ; and also pompholyx — for both 

 are produced by fire where the miners, breaking the hard rocks in drifts, tunnels, and 

 shafts, burn the cadmia or pyrites or galena or other similar minerals. From cadmia is 

 made black, brown, and grey spodos ; from pyrites, white ponipholyx and spodos ; from 

 galena is made yellow or grey spodos. But pompholyx produced from copper stone {lapide 

 aeroso) after some time becomes green. The black spodos, similar to soot, is found at 

 Altenberg in Meissen. The white pompholyx, like wool which floats in the air in summer, 

 is found in Hildesheim in the seams in the rocks of almost all quarries except in the sand- 

 stone. But the grey and the brown and the yellow pompholyx are found in those silver 

 mines where the miners break up the rocks by fire. All consist of very fine particles which 

 are very light, but the lightest of all is white pompholyx." 

 Quartz Minerals. 



