538 Of Mineral Principles. Part III- 
Yellow Mundick. GRAIN-ORE 3 immerfed in a Spar of 
an Amethyftine colour. 
Another fort, like Silver Grain-Ore, in a Spar of the co- 
lour of that of Tin. So hard as to cut Glafs. 
A piece of MundickzOre in a white Spar, both Grained 
and Vein'd. 
A piece or two of Veined Ore from a Silver-Mine. 
Mundick^ Ore and Vitriol mixed with a White and Green 
Spar. 
Mundick. Ore, and Black. Daze , mixed with a Vein of 
White and Green Spar $ all lying between two firm Beds 
or Walls. Thefe Ores, by fome are called MockzOres. 
A MOCK-FIRE-STONE. Pyrites ftirilis. Outwardly, 
of the colour of poliih'd Steel. And radiated from the 
Centre, as the true Pyrites. But of a light and ufelefs fub- 
ftance. 
No fort of Mundick., that I find,either in the Ore, or per- 
fect, ftirreth with Acids. Every Metal hath its Marchafite : 
u la Ta? 6 wn ^ cn 1S fometimes added to them, inftead of Lead, {a) to 
(b) Dr. ' make them flow the better. But if too much, it robs them, 
vaik "' S Tra " ky over volatilizing them (b) in the Furnace. Out of molt 
Fire-ftones, may be made both Vitriol and Sulphur. 
SECT. III. 
Of ^Mineral Principles. 
BY Mineral Principles, I mean, neither fuch imaginary 
ones as fome have talked of: nor fuch as may poffibly 
have a real exiftence, yet were never feen folitary or uncom- 
pounded : but thofe which come within the cognizance of 
fenfe, fc. Salt, Sulphurs, and Earths 5 and fuch Bodies as 
are reduceable to thefe Tribes. For it feemeth to me, That 
mofi fubterranial Bodies are either compounded of 
thefe Three, or are hereinto refolved. So Copperas is the 
fait of a Metal 5 either as an ingredient in its Generation 5 or 
refulting from its Corrofion by fome Natural Menjiruum y 
equivalent to fuch as are applyed by Art. In like manner, 
a Boluses it feems to be the Bafc of molt Stones and Metals 5 
