y6 A SYSTEM OF 



SECT. LXVIII. 



The Third Order. 



The Garnet Kind, 'Terrte Granate<e. 



The matter compofing the fubftance of garnet, 

 and fchorl or cockle, except that frnall portion 

 which is metallic, does in its indurated ftate re- 

 femble the filiceous tribe, fo far as relates to 

 external appearance and hardnefs ; and therefore 

 I would willingly have followed the opinion 

 commonly received, of confidering thefe two 

 Jubilances as ariiing from one another, if I had 

 not been perfuaded to the contrary by the fol- 

 lowing qualities of the garnet. 



1. It is more fufible, in proportion as it con- 

 tains lefs metallic matter, and is more 

 tranfparent or glairy in its texture; which 

 is quite contrary to the filiceous kind. 



2. This is the reafon, perhaps, why the gar- 

 net, mixed with the fait of kelp, may on 

 a piece of charcoal be converted to a glafs 

 by the blow-pipe, which cannot be done 

 with the flints : and, 



3. Why the moft tranfparent garnet may, 

 without any addition, be brought to a black 

 opaque flag by the fame means. 



4. It is never, lb far as is hitherto known, found 

 pure, or without fome mixture of metal ; 

 and efpecially iron, which may be extracted 

 by the common methods. 



5. The garnet matter, during the criftallifa- 

 tion, has either been formed in fmall de- 

 tached quantities, or elfe has had the 

 power of {hooting into criftals, though 



clofely 



