42 EFFECTS of HEAT 
of the utmoft importance and accuracy were made in Aftrono- 
my and Natural Philofophy, the fyftems produced by the Geo- 
logifts were fo fanciful and puerile, as fcarcely to deferve a 
ferious refutation. 
One principal caufe of this failure, feems to have lain in the 
very imperfect ftate of Chemiftry, which has only of late years 
begun to deferve the name of a fcience. While Chemiftry was 
in its infancy, it was impoflible that Geology fhould make any 
progrefs ; fince feveral of the moft important circumftances to 
be accounted for by this latter fcience, are admitted on all 
hands to depend upon principles of the former. The confoli- 
dation of loofe fand into ftrata of folid rock; the cryftalline 
arrangement of fubftances accompanying thofe ftrata, and 
blended with them in various modes, are circumftances of a 
chemical nature, which all thofe who have attempted to frame 
theories of the earth have endeavoured by chemical reafon- 
ings to reconcile to their hypothefes. 
Fire and Warer, the only agents in nature by which ftony 
fubftances are produced, under our obfervation, were employ- 
ed by contending fects of geologifts, to explain all the phe- 
nomena of the mineral kingdom. ; 
Burt the known properties of ‘Water, are quite repugnant to 
the belief of its univerfal influence, fince a very great propor- 
tion of the fubftances under confideration are infoluble, or near- 
ly fo, in that fluid; and fince, if they were all extremely fo- 
luble, the quantity of water which is known to exift, or that 
could poffibly exift in our planet, would be far too fmall to ac- 
complifh the office affigned to it inthe Neptunian theory *. On 
the other hand, the known properties of Fire are no lefs inade- 
quate to the purpofe; for, various fubftances which frequently 
occur in the mineral kingdom, feem, by their prefence, to pre- 
clude 
* Tlluftrations of the Huttonian Theory, by Mx Profeflor PLAYFAIR, 430- 
