EXrERlMENTS ON ALLAKITe. ^Jjjj^ 



crucible, it became black, and had some resemblance ^o 

 gunpowder. It we.ghed 7*-2 ^rain^!. 



4. This substance attracted my peculiar attention, ia con-Thwexa« 

 sequence of its appearauce. 1 found it to possess the fol*« "^" * 

 lowing characters : 



a. It was tasteless, and not in the least attracted by the It&charactctk 

 inajj;net, except a few atoms, which were easily separated 

 from the rest. 



h. It was insoluble in water, and not sensibly acted on whea 

 Wiled in sulphuric, nitric, muriatic, or nitro-niuriatic acid. 

 -^^ c. Before the blowpipe it melted with borax and micro* 

 cosmic salt, and formed witb both a colourlesi bead. With 

 carbonate of soda it formed a dark-red opake bead. 



d. When heated to redness with potash, and digested in 

 water, snuff-coloured florks remained undissolved, which 

 gradnully subsided to the bottom.. The liquid being sepa- 

 rated, and examined, was found to contain nothing but 

 potash. When muriatic acid was poured upon the snufF« 

 coloured flocks, a slight effervescence took place, and when 

 heat was applied, the whole dissolved. The solution was » 

 transparent, and of a yellow colonr, with a slight tint of 

 green. When evaporated to dryness, to get rid of the 

 excess of acid, a beautiful yellow matter gradually sepa* 

 rated. Waten boiled upon this matter dissolved the whole. 

 The taste of the solution was astringent, with a slight 

 metallic favour, by no means unpleasant, and no sweetness 



was perceptible. 



e. A poi*tion of the black powder being exposed to a red 

 heat for an hour, in an open crucible, became reddish- 

 brown, and lost somewhat of its weight. In this altered 

 state, it was soluble by meajis of heat, though with diffi?- 

 culty, both in nitric and sulphuric acids. The solutions 

 had a reddish-brown colour, a slight metallic astringent; 

 taste, but no sweetness. 



/. The solution of this matter in nitric and muriatic acid, Action of ro. 

 when examined by reagents, exhibited the followiiig pheno- '»?^"!^ "" *<* 

 nomena: 



(I.) With prussiate of potash, it threw down » white pre^ 

 cipitate in flocks. It soon subsided ; readily dissolved 

 in nitric acid; the solution was green. 



