CUPRUM vitriolatum (vitriol of copper) and vitriol of iron contaminated by zinc. Such is found at Fahlune.
CLASS II.
EARTHS.
Before we can underſtand the nature of earths, we muſt know their component parts. Thoſe earths which cannot be further decompoſed we call primitive, and thoſe which conſiſt of two or more of theſe intimately united, derivative. By this union we do not mean a mere mechanical diffuſion, at leaſt not ſuch as can be diſtinguiſhed by the eye, as is the caſe in ſtones, (ſaxa.)
It is evident that the primitive earths will conſtitute ſo many natural Genera, and different mixtures of theſe the Species.
They who would make ſeveral Genera out of one primitive earth, muſt ſeparate the glaſſy, red, white, horny ſilver ores, and other different compoſitions into as many Genera, or elſe act inconſiſtently with their own principles.
At preſent we only know five primitive earths. They who reckon fewer, reſt their opinions upon fanciful metamorphoſes unſupported by faithful experiments[[37]]. As experiments teach us that there are five primitive earths, it is evident that the Species ariſing from the mixture of theſe cannot exceed twenty-four, viz. 10 double (conſiſting of two earths) 6 triple, 3 quadruple, and the 5 primitive.