[ 58 1 
I. STONES, as tliey evidently have their origiii from hardened 
compadl Earths, fnto which they again moulder, cannot 
without unnatural feparation but be joined wi h them in the 
fameclafs. They refill fire, the greateft degree of which is 
not not able to refolve any of their particles into vapour. 
They are all of them without talle, and moil of them without 
odour. 
1. Talcose, are mod of them foft and very foft, principally 
contain Magnefia alba, and never have the veftiges of living 
bodies. They occur in primary mountains, more often in 
fecondary, fonie compofe ftrata or the principal parts of 
mountains, and others are parafitical. By the adion of fire 
they are not calcined, nor, except Hornblenda Adinotus and 
.erriierous Afbeftus, are they litjuifiablc, but become harder. 
2. Ponderous, exceed all others in fpecific gravity, are more 
eafily liquifiable by fire, always parafitical, never have the 
veftiges of living bodies^ are foft and hardilh, and chiefly 
confift of Terra pondcrola properly fo called. 
3. Calcareous, fome are formed of teftaceous fubftances and 
corals, fome are primitive, others are rupeftria! or parafitic, 
many are filled witli the veftiges of living bodies ; they are very 
foft, foft, and hardilh ; become more porous by fire ; the purer 
ones all effervefee, and are almoft totally dilfolved in nitrous 
acid or Aqua fortis. 
4. Argillaceous, fome are very foft, plaftic, flicking to the 
tongue, when moiftened give out a peculiar odour, hardening 
in the fire, and have often the imprellions of animals and ve- 
tables upon them; fome are foft or hardilh, and are rather 
liquified than hardened by fire, of which the principal part 
arc rupeftrial; others, though fewer in number, are hard, and 
undergo the fame change by fire. * 
5. Siliceous, are hard and very hard, and, except the fluoric, 
are not affefttd by acids, certainly in part ; fome are rupeftrial^ 
others parafitic, and thefe laft have often the veftiges of livine 
bodies, ^ 
6. Adamantine, is very hard, parafitical, containing an earth 
peculiar to itfelf, and hitherto deteded in no other folTil. 
