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The proportion of the different materials contained in the 

 chaotic fluid to each other may be fuppofcd upon the whole 

 nearly the fame as that which they at prefent bear to each other, 

 the filiceous earth being by far the moft copious, next to that 

 the ferruginous, then the argillaceous and calcareous, laftly the 

 magnefian, barytic, Scottifh and largonic, in the order in which 

 they are named, the metallic fubftances (except iron) moft fpar- 

 ingly ; in particular parts however of this polygenous fluid a very 

 different proportion muft have obtained (as in fome parts of the 

 globe) fome fpecies of earth or metal, &c. have evermore been 

 found more copious than in others. Some geologifts, as Buffbn, 

 and of late Dodor Hutton, have excluded calcareous earth from 

 the number of the primasval, aflx;rting the maflies of it we at Ipre- 

 fent behold to proceed from fhell filh' But in addition to the 

 unfounded fuppofition, that ftiell fifh or any animals pofl!efs the 

 power of producing any Ample earth, thefe philofophers fliould 

 have confidered that before the exiftence of any fifli the ftony 

 maflTes that inclofe the bafon of the fea muft have exifted, and 

 among thefe there is none in which calcareous earth is not found. 

 Of this circumftance indeed Buffbn was ignorant, the analyfes 

 that prove it being unknown to him. Do6tor Hutton endeavours 

 to evade this argument by fuppofing the world we now inhabit 

 I to have arifen from the ruins and fragments of an anterior, and 

 that of another ftill prior, without pointing at any original. If 

 we are thus to proceed in infinitum I ftiall not pretend to follow 

 him, but if he flops anywhere, unlefs he alfo fuppofes his primi- 

 VoL. VI. H b tive 



