6 
minerals. 
fiinilar incorporation. Staladite accretes with a cryftalliae cover- I 
ing, in like rnanner as calculus; and no one will venture to flip- ! 
pole that cryltals can exift without fait, or deny that the earth is 
cryilaliixed by falts,. Their tranfparency is derived from their 
atomical conltniaion, and their colour from metals. The vaiue 
of gems is according to their tranfparency, hardnefs, permanency 
and colour; and from their being the principal inftruments of hu- 
man lu.xury, are often imitated by the fratidsof trade. 
VITRIOL, the produft of .alum, intimately a'lied to metal i.s of 
different appearance and figure according to the nature of the me- 
ta', of which the mold freejuent are Iron, Coppi^r, and Zinc • 
fome therefore mold commonly become lidphuieous Pyrites others 
terrene Ochres. Oilferent Pyrites atfuine different figure', wliofe 
parth into which it is refolved is ufually denominated Ochre, wiiicli 
when proceeding from Iron is yellow, and becomes red when 
burnt ; when from Copper by acid is green, by alcali blue : lb that 
ilones which are yellow or red, are pincipally from Iron- tliofe 
which are green or blue, from Copper. Each'kiiid ot Ochre In' 
cryftallization, coagulates earths into i 
]METALS are fupradecompoun.l, and confid of Earth Salt, and 
Sulphur. Iron, whenever prefent, is often tiiffolved by the e!e- - 
ments; am! v/hen dilfolved by vitriolic fah and an ocraccous earth I 
precipitated, Iron by cryfdallization cements earths into ftoucs, and ! 
ablbrbed is multiplied by metal, and lo produces many times more 
than it had primarily received. Vitriol liagnating in the fiifures of 
rocks retaining wmter, wheii multiplied ami precipitmed by a lon<’- 
lapfc of time, patfes into a vein, which when opened tranfverfely 
and filled up with a different earth, vyill forthwith change the me- 
tallic vein into, a different one; as from Iron or Copper, Lead often 
becomes enriched with Silver, Av. For the faipe vein ’ by vai iable 
inodificatiou, may abound in Alum, Vitriol, Arfenic, Sulphur 
Iron, Copper, Cold, Silver, Antimony, Lead, Zinc, orBilmmii. ’ 
ROCKS, appearing like ttie prominent bones of the caiih, are of 
great bijlk, folidity, and longevity ; compolbd of fand, gravel, opake 
and diaphanous fioues, with every where argillaceous and often 
talcofc fiibfiances intermixed; and are at lenglVcemcnted into more 
folid malfes, with a various and irregular mixture of cryilals of 
Qiiartz, Mica, and Spjv That thefe are the olLpring of time i 
and the llrata ot nature, no one will doubt, whofc coullitucnt parts ^ 
are to every one palp-able. In thefe ihe metalliirgifl. will diCcover i 
the matrices of minerals, many-fhaped from their mixture and 
diverfified in fire. ’ 
RETRIFACTIONS are rather the parents than tlic produd of 
fliarmoreous mountains, and may confifl of as many diverfificatiyns 
