1 26 Elements of Mineralogy. 



SPECIES XIII. 



Siliceous Earth imperfectly united to about 0,7 

 of its weight of Argill^ and -1 of its 'weight 

 of Calcareous Earth, without Iron. 



Vefuvian Garnet. 



It is improperly called a garnet, as it con- 

 tains no iron, and it differs from zeolyte in 

 containing no water, and alfo in texture and 

 hardnefs : its colour is white, fometimes 

 opake and fometimes tranfparent, and very 

 hard : it is difficultly acted on by any of the 

 fluxes. 



According to Mr. Bergman, it contains 55 

 per cent, of filiceous Earth, 39 of argill, and 

 6 of calcareous Earth. 



SPECIES XIV. 



Siliceous Earth more or lefs perfectly united to 

 0,63 of its weight of Argill, about 0,4 of 

 its weight of Calcareous Earth, and from 

 0,28 to about 0,41 of its weight of dephlo- 

 gifticated Iron. 



Garnet. 



When not over-loaded with iron it is tranf- 

 parent, though, from the intenfity of its co- 

 lour, 



