Simple Earths. 3 



Stones differ from Earths only in hard- 

 fiefs and its confequences, and therefore are 

 included under the fame generical name. 

 Yet diamond is alfo called a Stone, though 

 it probably contains little Earth of any kind. 



CHAP. I. 



Of Simple Earths, their number and Char alters. 



By fimple Earths, I mean thofe which pof- 

 feffing permanently diftind: Characters, are 

 ihcapableof being further analyzed or changed 

 into any other, by any means hitherto known. 

 Of thefe, we know only five. The Calca- 

 reous, the Ponderous, the Magnejlan or Mu~ 

 riatic, the Argillaceous^ and the Siliceous. 

 All Stones and Earths hitherto examined, are 

 fdund to confift of thefe either iingly, or 

 mixed, orchymically united wjth each other, * 

 in various proportions, together with faline, 

 inflammable and metallic Jubilances ; for in 

 the Earth they are feldom or ever found per* 

 feclly pure. 



Of the Characters of Calcareous Earth. 



i ft * When perfectly pure and free from all 



combination, it conftitutes lime ; its fpecific 



gravity is about 2,3. it has a hot burning 



tafte, acts powerfully on animal fubftances, 



B 2 and 



