OF FOSSILS. 30; 



S cxcur. Denomination of Genera. 



EACH genus fliould be cxprefTcd in one word, 

 for the fake of brevity and convenience. 



Among the falts there arc, flriclly fpcaking, 

 but two genera ; the acid und the alkali. And 

 we fliaU fee by and bye the great advantage this 

 produces, that the combinations of every acid 

 conftitute proper genera. An acid may be con- 

 fidered fubfluntively without the nccefllty of 

 having the word Salt prefixed to it, as every a- 

 cid is a fait. 



In the fccond clafs we have found five gene- 

 ra. One of which, but lately difcovcred, has, 

 on account of its fpccific gravity, obtained the 

 name of Terra Pondcrofa. But in order to ren- 

 der it more concifc and convenient, the firft 

 word might be cadly omitted, though always 

 undcrflood, and the lall employed alone as a 

 fubftantiyc ; or we would, with Monf. dc Mor- 

 vcuu, adopt Bnritcs from /*,-.* with great advanj 

 tage. The remaining earths are all cxprcfled 

 with fubflantivc names; but for the lake of per- 

 fpicuity, I would yet recommend fomc alterutj. 

 on in tlicm: As for example, Culx,Magnefm,Ar- 

 gilla, and Silex, arc dcfcriptivc of fottiJs, fuch as 

 they occur on the furfacc of the earth, bicntiul 

 more or lefs with heterogeneous matter ; and 

 therefore the words Calcarcum, Mugnefium, 

 U Avgiiiaccurp, 



