162 Description of a new Mineral Species. 



Chemical Description and Analysis. 



When heated before the blow-pipe, it emits a phosphorescent 

 light, and fuses into a white porcelainous mass, which on being 

 laid upon moistened turmeric paper, imparts to it a brown stain. 

 It is partly soluble in hydro-chloric acid with effervescence : and 

 the solution, on being treated with alcohol and set on fire, burns 

 with a scarlet-red light. The nitric solution, on evaporation to 

 dryness, again becomes moist after a short exposure to the air. 



A portion of the mineral, in the state of an impalpable powder, 

 was digested in hydro-chloric acid, so long as any matter contin- 

 ued to be taken into solution. The undissolved portion was sep- 

 arated from the fluid, and after careful washing with warm wa- 

 ter, was dried and ignited along with powdered charcoal in a 

 porcelain crucible, for one hour. Boiling water was aflfused, and 

 the clear yellow solution of hydro-sulphuret separated by the filter 

 from the unconsumed charcoal. Hydro-chloric acid was added 

 to one portion of the solution, and after partial concentration by 

 boiling, alcohol was added. It burnt without any indication of the 

 presence of the chloride of strontium. The remainder of the hy- 

 dro-sulphuret was decomposed by nitric acid, and the solution 

 evaporated to dryness. A minute scale of the salt was added to 

 a solution of sulphate of soda. It instantly produced a cloudi- 

 ness, nor was the precipitate re-dissolved on the addition of more 

 water. The solid nitrate (obtained by evaporation) moreover, re- 

 mained exposed to the air for twenty four hours, without sensible 

 deliquescence. 



It hence appears that the sulphate contained in the mineral, is 

 neither (wholly nor in part) that of strontita, or lime. The spe- 

 cific gravity of the mineral, taken with the crystalline form it as- 

 sumes, can leave no doubt of its being sulphate of baryta. We 

 have seen above, that carbonic acid, lime and strontita, are also 

 constituents of the mineral. The quantitative analysis was con- 

 ducted as follows : the carbonates were dissolved out by nitric 

 acid. The insoluble sulphate was washed, heated to redness, 

 and weighed. The nitric solution was evaporated to dryness and 

 treated with alcohol, having a specific gravity 0.812. The alco- 

 holic solution was evaporated to dryness, and the nitrate of lime 

 decomposed by a white heat. The nitrate of strontita, still moist 

 with alcohol, was introduced along with the filter into a small 



