188 Dr Thomson's Chemical A7ialysis of an Indian Mesolite. 



liquor was now evaporated to dryness, and the residue subjected 

 cautiously to a red heat, to dissipate the ammoniacal salts. A 

 white substance remained, which weighed 1.5 grains. When 

 dissolved, it yielded a precipitate with nitrate o' silver, but none 

 with muriate of platinum, or when boiled with carbonate of 

 soda. It was therefore chloride of sodium, equivalent to .70 

 soda. Ten grains of the mineral were rendered opaque by a 

 red heat, and lost of their weight 1.471 grains. The Indian 

 specimen of mesolite thus afforded, 



Silica, .... 4.270 42.700 



Alumina, . . . 2.750 27.50 



Lime, 761 7-61 



Soda, 700 7-00 



Water, .... 1.471 14.71 



9.952 99.52 



The formula to represent its constitution most nearly, will be 



3AS + aC + 4N) 8^ + 31 Aq. 



which approaches closely to a Bohemian specimen analyzed by 

 Dr Freysmuth, with a specific gravity of 2.333.* The results of 

 three analyses of mesolite afford formulae differing in the rela- 

 tive proportions of soda and lime, and in the quantity of water. 

 These are in the order of their increase, 



3 AS + (I C + ^N) S' + 2| Aq. Iceland. Fuchs. 



3 AS +- (4 C + 4N) S' + 3 Aq. Bohemia. Freysmuth. 



3 AS + (4 C + IN) S^ + 34 Aq. India. 



which it is obvious may be resolved into the general expression, 



3AS+(N)s^+3Aq. 



These formulae are calculated according to Dr Thomson's 

 atomic weights, reckoning the atoms of silica % and that of alu> 

 mina 2.25. The mineral belongs to the V. Genus Alumina, of 

 his 2d Class Alkalies and Alkaline bases, in his new chemical 

 arrangement of minerals. 



• Schweigger's Journal, xxv. 426. An. of Phil. xvi. 405. 



