HUTTONIAN THEORY. 



99 



tfc 



«i 



) 



[(• 



f 



fure trace, there are others known to us only by 

 their effeds. 



" inflance, the pureft rock cryflal 



We fee, for 

 affedcd by expofure to the weather, its luftr 

 tarniflied, and the poliHi of its furface impaired 

 but we know i 

 thefe operation 



othing of the power 

 5 are performed. Tl 



b 



wh 



the precautions which the mineralogifl takes to 



preferve the frefli fra(5ture of h 



fp 



have a proof how indifcriminately all the pro- 



i foffiL kingdom are expofed to 



duclions of th 



the 



ks of th 



and we 



perceive how difficult it is to delay the begi 

 nings of a procefs which no power whatei 



n finally count< 



r 



gS' The mech 





a 



forces 



difinteg 



of mineral fubfta 



ployed 



th 



afily marked than the ch 



are more 



He 



d 



appears as the moil afti 



eag 



ya 



d bodies 



my of hard 



d 



in 



fp 



y it 



fr 



e 



cj 



inccffantly 



pour to folid ice, from the fmalleft 

 the greatefl river, it attacks w^hatever has 

 id above the level of the fea, and labours 



ftore it to the deep. ^ The parts 

 loofened and difengaged by the chemical agents, 

 are carried down by the rains, and, in their de- 

 fcent, rub and grind the fuperficies of other bo- 



though incapable of ading- 



d 



Th 



on hard fubilances by dired attrition, 



G 



is th 



cauf 





