284 M. Gritner Ober-Berg on [April, 



The specific gravity of the crystallized mineral I found to be 

 3-5906 at the temperature of 72^". 



The chemical analysis of this mineral was conducted by me in 

 the following manner : 



(A.) Two hundred grains of the mineral were reduced to a fine 

 powder, exposed for half an hour to a red heat, and then weighed 

 while still hot. No alteration in the weight could be perceived. 



(B.) One hundred and fifty grains ofthe mineral were reduced toa 

 fine powder in an agate mortar, mixed with thrice their weight of 

 carbonate of potash, and heated for two hours so strongly in a 

 silver crucible that the mass had melted. The matter when cold 

 was softened in distilled water, and then washed till the water 

 employed for that purpose ceased to be acted on by reagents. 



(C.) The alkaline solution obtained in tliis way was supersatu- 

 rated with muriatic acid, evaporated to dryness, the dry mass 

 was redissolved in distilled water, and the excess of acid satu- 

 rated with potash without any muddiness or precipitate making 

 its appearance. 



(D.) The earthy residuum was now treated with muriatic acid^ 

 in which it dissolves completely, and the solution was accompa- 

 nied by a strong effervescence. Into this muriatic solution was 

 added an excess of ammonia, whereby a small quantity of a light 

 brownish-red precipitate was thrown down, which, when dried 

 and heated to redness for half an hour in a platinum crucible, 

 weighed 0*32 gr. I dissolved it in a few drops of muriatic acid, 

 diluted the solution with water, and mixed it with prussiate of 

 potash, by which the iron was thrown down in the state of a 

 prussiate. The liquid thus freed from iron being mixed with 

 ammonia deposited some alumina, but the quantity of it was so 

 small that it could not be weighed. This 0'32 gr. constitutes the 

 ferru2;inous alumina with which the strontian is mixed in the 

 mineral. 



(E.) The liquid thus supersaturated with ammonia was evapo- 

 rated to dryness in a porcelain vessel, the dry residue was 

 heated to redness in a platinum crucible till all the sal-ammoniac 

 was driven off. It was then reduced to a fine powder, and digested 

 in 16 times its weight of alcohol. The alcohol was raised to the 

 boiling temperature, and decanted, while boiling hot, from the 

 undissolved residuum. 



The alcoholic solution on cooling let fall fine needle-form 

 ciystals. These crystals continued to be deposited during the 

 evaporation to the very last drop. The crystals thuf^ obtained 

 were divided into two equal halves. The one was employed in 

 experiments to learn the nature of the salt. It exhibited the 

 properties of muriate of strontian. The remaining half of the 

 crystals were dissolved in water, and the solution poured into 

 the alkaline ley (C) saturated with muriatic acid. A white heavy 

 powder fell, which was sulphate of strontian. Tliis regenerated 

 sulphate of strontian weighed, after being heated to redness in a 



