ANALYSMr 259] 



them were tinged of a fmoke-colour. They foon became Defcription an4 



deliquefcent. Upon evaporation, the fame crvftallizations ^".^'>^? °^* 

 1 1 AT • r 1 , . . , mineral from 



were produced. Altera time, lome detached, regular, and Cornwall. 



permanent cry (la's were formed, which were colourlefs. 

 Their figure I could not accurately afcertain. They were 

 expofed to a red heat in a platina crucible. No ammoniacal 

 vapour was perceptible. The cryftals melted into opaque 

 globules : fome of thefe were transferred to a fmall glafs, and 

 diftilled water was poured upon them. No folution took 

 place apparently ; on fliaking the glafs, the globules fell to 

 pieces into gelatinous flakes, which were white. Some of 

 the fupernatant fluid was tried with muriate of barytes, which 

 produced a cloud. But neither ammonia nor prufllate of 

 potafli cauled any change in it. It is foluble alfo in nitric 

 acid: the folution formed a confufed cry'ftallized mafs, which 

 foon became deliquefcent. Zinc, iramerfed in it, caufed the 

 feparation of white gelatinous flakes. Iron caufed no change. 

 Ammonia and potath threw down white precipitates, a por- 

 tion of which were redilTolved. The carbonates of foda, 

 potafli, and ammonia produced white precipitates. Prufliate 

 of potafli tlirew down the contents of the folution in diftin€t 

 flakes, of the colour of mahogany ; and the folution of galls 

 in alcohol caufed a light yellow powder to fubfide. It is 

 foluble alfo in muriatic acid; the folution is a very dilute 

 green. It requires an excefs of acid to hold the fubftance in 

 folution : which, after a time, depofits cryftalline grains of 

 a yellowifli colour, which require a large quantity of waV* 

 to diflTolve them. 



Acetic acid does not diflTolve this powder. 



(8.) What was diflx)lved by potafli (3.) was of an ifabella 

 colour : it was tried with nitric, muriatic, and fulphuric acids, 

 neither of which could difiblve the whole of it. What re- 

 fifted the two former acids was found to be lilica. That 

 which remained undiflToIved by the latter, was fiHca and 

 fulphate of lead. Evaporation of the latter folution, be- 

 trayed alfo the prefence of lime, in the ftate of fulphate. 

 The nitric and muriatic folutions, on evaporation, depofited 

 nitrate and muriate of lead ; and fulphuric acid dropped into 

 thera produced a tmall quantity of fulphate of lime. 



The nitrate and muriate of lead were decompofed by ful- 

 phuric acidj and the lead reduced on charconl. 



Ammonia 



