ANALYSIS, Q55 



of (he cryfials into a fmall retort, ada|>ted a receiver unto it,D«fcript'ion?ix4 



and expofed the retort to a charcoal fire. The neck of the ^"^yfis of a 

 f 1 • n 1 • 1 ^ I mineral trora 



retort was foon covered with moifture, which pafled into the Cornwall* 



receiver J and I obferved a white cruft gradually forming in 



the arch and neck of the retort. 



On examination of the fluid in the receiver, it was found to 

 have the fame empyrenmatic fmell that I had obferved before. 

 It refembles very much the fmell which that fluid is found to 

 have which is diftilled from the white cruft that furrounds 

 flint as a nucleus. 



It changed litmus paper to a faint reddifh hue. It produced 

 no change on a folution of nitrate of filver, and fcarcely a per- 

 ceptible one, on that of nitrate of mercury. 



The crufl formed in the neck of the retort confifted of thia 

 fcales, which after the vefTel had been dried, were difpofed 

 to feparate from the glafs in fome places, but in others they 

 lirmly adhered unto it. Thoy were opaque, like white ena- 

 mel, and refle6led the colours of the rainbow. A portion 

 of this fubflance expofed to the flame of the blow-pipe upon 

 charcoal turned at firft black, and then melted into a globule, 

 that exhibited fomewhat of a metallic fplendor which foon 

 grew dull. This fubflance is foluble in water ; on evapora- 

 tion of it, it afTumes, at the edges of the fluid, a faline appear- 

 ance, which, as the moifture evaporates, becomes earthy, 

 opake, and white. Some of the folution changed litmus 

 paper to a faint red. Lime and ftrontian waters produce in 

 it white clouds, which a drop of nitric acid removes. Mu- 

 riats of lime and barytes produce no change in it. Nitrate 

 and acetate of barytes difturb its tranfparency, the effect 

 produced by the latter is more evident. Nitrate of filver 

 produces no effed, but nitrates of mercury and lead caufe 

 ^ropious precipitates, which are white and foluble in nitric 

 acid. Phofphate of ammonia and foda produced a white 

 precipitate. Oxalate, tartrite, and prufliate of potafli did 

 not affect it, nor did fulphate of foda. Ammonia was 

 dropped into it, but the fluid preferved its tranfparency. But 

 carbonate of ammonia inflantly caufed a white precipitate, 

 which was not rediflTolved by an excefs of the precipitant ; 

 upon fome of this fabfided precipitate a concentrated folution 

 of polaHi was poured and fliaken with it, fcut it was not 

 T 2 fenfibl/ 



