Page:De re metallica (1912).djvu/156

114 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 any 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 sublimatum). 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 pompholyx 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 sandstone. 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."