From STRONTIAN. 15 



form of a white powder. This acid, poured into Strontitic wa- 

 ter, unites with the earth, and precipitates with it. 



35. This is one of the mod infipid, and one of the mofl: in- 

 foluble of the combinations into which Strontites enters. Ten 

 grains were boiled in four ounces of diftilled water for feme 

 minutes, there remained undiUblved fully nine grains. The 

 clear liquor had the flighted poffible degree of milkinefs produ- 

 ced in it, on the addition of fulphuric acid, or of carbonate of 

 potafs. By heat the oxalic acid is deftroyed, and the earth rcr 

 mains partly pure and partly united to carbonic acid.. 



With I'artarous Acid, 



36. With this acid the mineral exhibits appearances nearly 

 fimilar to thofe now defcribed. There is however, for a fliort 

 period, an extremely feeble effervefcence. Here I may remark, 

 that for the fake of promoting the union of Strontites with: 

 the weaker acids, I frequently employ what I call the artificial 

 carbonate of Strontites, by which I mean this earth precipitated 

 from an acid by an effervefcent alkali. On this powder the acid' 

 of tartar a6ls with vigour. When dropped into Strontitic wa- 

 ter, it carries down the Strontites in union with it. 



37. The tartrite is nearly infipid. I boiled ten grains of it 

 in ^four ounces of diftilled water ; fix grains were diflblved. 

 This folution, after it had ftood fome weeks in a clofe phial, 

 depofited during frofty weather feveral fmall but very regular 

 cryftals, the form of which is a triangular table, having the 

 edges and angles fliarp and well defined. Thefe cryftals under- 

 go no alteration from expofure to the air. When adled upon by 

 heat, they at firft fwell and are puffed up after the manner of 

 borax, and at length with ignition lofe their acid, which is the 

 firft change that the powdery tartrite fuffers under fimilar treat-?- 

 ment. 



Witb'j 



