OF FOSSILS. 



$ cxxxi. Species of Earths of a double Cbnraftcr. 



In the clafs of cartlis different fpccics frequent- 

 ly occur, pofleffing two characters. To the fird 

 belong the falinc earths; which, on account of 

 the limits before nttigncd to them, arc not rec- 

 koned in the clak of falls, although they refera- 

 ble them in their nature, and conflitutc but an ; 

 imperfect fpccies of earths. Of thcfe fubiianccs^ 

 however, a few only are known, 51. 



cxxx 1 1 . Mixed Species of Etirtbs. 



GENUINE fpccies of mixed earths arc produ- 

 ced by the intimate union of two or more. Of 

 the exidcncc of fuck au union we have clear c- 

 vidcncc, in 90, 



> cxxxin. On what Arguments their Diverjity is . 

 founded. 



Not the quality and number only of the in- 

 gredients, but even their relative weights im- 

 ply a fpccific divcrfity. 



cxxxiv. The NcceJJity cf confide ring tbc Propor- 

 tion of every Part. 



In the Sciagraphia Rcgni Mineralis, lately 



publilhcd 



