TABLE SPAR. 183 



colourless glass. Hardness between common glass 

 and carbonate of lime. Specific gravity 2. 89. Ac- 

 companying this mineral are small grains of cocco- 

 lite, whose colour is brown and green ; the former 

 ones, no doubt belong to Garnet, the latter, from pos- 

 sessing natural joints, seems to be a distinct sub- 

 stance. 



The mineral in question, forms a jelly with muri- 

 atic acid : loses nothing by calcination, although 

 maintained for half an hour at a red heat : on ex- 

 amination, I found it to consist of Silex, of Lime, and 

 a small quantity of oxide of Iron. Its analysis was 

 made in the following manner. 



150 grains were boiled with muriatic acid, as long 

 as any part appeared to be unattacked; water was 

 then added and the solution filtered, the Silex an in- 

 soluble part when calcined, weighed 77 1-2 grains. 

 That no uncertainty should exist with respect to the 

 quantity of Silex, it was a second time repeated upon 

 another portion of the mineral, with precisely the 

 same result. 



To the liquor from which the Silex had been se- 

 parated, carbonate of ammonia was added until it 

 ceased to give any further precipitate ; this was se- 

 parated by filtering, when well dried, it weighed 

 121 grains; and consisted of carbonate of lime, 

 slightly coloured with oxide of Iron. It was set aside 

 for further examination. The ammoniacd liquor 

 was evaporated to dryness, then calcined ; nothing 

 remained but 4 i-% grains of muriate of Lime ; which 

 had escaped decomposition. 



