C ^9 1 
Rocks are from their nature fought for in their mother Earth, 
The Mothers of Earths are principally four: 
Soil, muddy, vegetable, combuiHble. 
Calx, tellaceous, animal, effervcfcing. 
Clay, apyrous, atjuatile, hardening. 
Sand, moveable, aquatile, hardened. 
I. Humose, from vegetable earth, flaming and combiiftible when 
burnt. 
Soil is the flow depofition of waters, and is therefore horizon- 
tally fiffile. 
Argillaceous particles are often depofitcd with foil, by which 
Schift becomes more or Icfs argillons. 
Mineral acid from marrties fumetimes gives it a tinge of Iron, 
And when burnt they . produce a red ochraceous earth. 
In burning they are confumed, unlefs when mixed too much 
with metal. 
II. Calcareous, from teftaccous fubftances or Lythophytes 
changed into earths. 
For all calx is produced from the animal kingdom. 
Effervejcenf and foluble in acids, and thererore are alcaline, un- 
lefs they have been previoufly faturated with acid, as Gypfum. 
Burnt and extinguilhed by water they fall into a branny powder. 
By the power of calcination or petrifaSiion they become multi- 
plicative, in humofe, vegetable, animal, and probably calca- 
reous fubftances. 
III. Argillaceous, from a vifeid marine matter coagulated 
into earth. 
Raftle&z lubricous when reduced, fince they are of a foft vifeid origin. 
Hardening, they become dryer and harder by the adlion of fire. 
They w-ere formerly denominated apyrous. 
I\^ Arenate, from atoms of water united into an arenaceou* 
fubftance. 
They have their origin from astherial rain water. 
Particles, hard, rough, leaving a mark. 
Striking fire with fteel from their folidity and hardnefs. 
They were formerly denominated vitrefeent. 
V. Aggregate, from mixed particles of the preceding orders. 
Hardening, from whatever earth, porous.. 
Their hollow' interftices were filled up with terreftrial water, 
which becoming folid particles added a mixture of Quartz, 
Spar, Mica. 
In ignition they are to be confidercd according to the qualities of 
which they are compofed. 
