Fossils. 



dress ofthe fair, or decorate the furniture 

 of the opulent ; and others, melted by fire, 

 form the transparent glass. 



Although there seems to be an almost 

 infinite variety of earthly substances scat- 

 tered on the surface of this globe yet when 

 we examine them chemically, \ve find 

 that all the earth and stones which we 

 tread under our feet, and which compose 

 the largest rocks as well as the numerous 

 different specimens which adorn the cabi- 

 nets of the curious, are composed of a 

 very few simple or elementary earths, the 

 principal of which are the calcareous, si- 

 liceous, argillaceous, magnesia, terra pon- 

 derosa, and a few others which have been 

 discovered lately, but have not been much 

 examined. 



Calcareous earth is found in the shells 

 of fishes, the bones of animals, chalk, 

 limestone, marble, and gypsum : but all 

 calcareous earth is supposed to be of 

 animal origin ; and beds of chalk, lime- 

 stone, or marble, are thought to have 

 been beds of shells formed in the sea, in 

 some pristine state of the earth. 



Silex, or siliceous earth is the princi- 

 pal constituent part of a great number of 



