Analysis of Argentine and Steatite. 335 



acids, is too well known to make a more detailed statement 

 necessary in the present case. Muriatic acid dissolved all 

 the mineral except the silex, which weighed 50.6 grs. From 

 the muriatic solution carbonate of ammonia threw down the 

 oxide of iron, being 3.25 grs. equivalent, according to Brande, 

 to '2.59 grs. of protoxide of iron. Pure potash separated 

 the alumine, estimated at 0.15 gr. The ammoniacal solu- 

 tion contained the magnesia and oxide of manganese. This 

 solution was evaporated, and the ammoniacal salts were 

 separated by sublimation ; the magnesia and manganese 

 remained. They were then converted to sulphates ; the 

 solution evaporated to dryness, and the dry mass was kept 

 at a red heat for half an hour. The water was thus driven 

 off from the sulphate of magnesia, and the sulphate of man- 

 ganese being converted to the deutoxide of manganese, a red- 

 dish powder was thus diffused through the sulphate of magne- 

 sia. The whole weighed 87.5 grs. and dissolved in water 

 except one grain of deutoxide of manganese, equivalent to 

 1.1 gr. of the peroxide. This contained, therefore, 86.5 grs. 

 forthe sulphate of magnesia, equivalent to 28.83 grs. of pure 

 magnesia. The result is, 



grs. 



100.00 



This result contains a proportion of ingredients between 

 those given by Klaproth in his analysis of steatite from two 

 different places. There can be no doubt, therefore, that 

 these crystals are real steatite. 



The /orm of some of these crystals, is that of a six-sided 

 prism terminated by six-sided pyramids, often variously 

 truncated. Some of them appear to be four-sided prisms 

 terminated by a four-sided pyramid. They are unques- 

 tionably the crystals intended by Jameson, as they are 

 found HI a similar situation to those mentioned bv him. 



