214 New Metal discovered ly M. Tromsdorff, 



M. Thon took this fossil at the first view for anthracite ! 

 he held a small bit of it above the flame of a lamp for the 

 sake of assuring himself of its incombustibility; but it in- 

 flamed, took fire, and burnt with a pale blue flame. Some 

 drops flowed, which were crystallized in stars, and were 

 surrounded with a yellow rim. The mineral, when melted 

 further, kept the same colour. On dropping some nitric 

 acid on some bits gf the mineral, the acid did not appear 

 for some time to attack it; but by the aid of heat it changed 

 it to a reddish brown, and by ebullition dissolved it, taking 

 to itself a yellow colour. To assure himself that the mi- 

 neral did not contain any mercury, M. Thon rubbed it on 

 a plate of silver, to which it communicated a yellow colour, 



M. Tromsdorff tried, with ths small quantity of the mi- 

 neral which he had been able to procure, the following ex- 

 periments : 



1. Five grains of the mineral were put into a small cylin- 

 der of glass, open on one side and exposed to the action of 

 fire. They melted like wax, and spread a very strong sul- 

 phurous odour. 



There was deposited on the sides, at the top a white sub- 

 limate, lower down a sublimate of yehow sulphur, lower 

 Biill an orange-coloured sublimate, and finally a crystalline 

 black sublimate, having a metallic lustre. The whole was 

 then volatilized — the cylinder was put sideways. 



2. Five grains of the fossil were exposed to heat with 

 some nitric acid : the mineral acquired a red-brick colour, 

 and the acid attacked it stroiigly, disengaging nitrous acid. 

 The solution was evaporated to dryriess, and a powder was 

 obtained of a red colour which emitted a strong smell of 

 sulphur. The powder was boiled with water, in which it 

 was dissolved excepting nearly a grain, which had the co- 

 lour of sulphur, and which burnt with the usual flame and 

 smell of tliat combustible. 



3. The solution (2.) contained some free nitric acid, and 

 perhaps also sulphuric acid. The redundant acid was sa- 

 turated with ammonia, and the solution was decomposed 

 by several reagents. 



a. Prussiate of potash produced a beautiful green pre- 

 cipitate. 



I, Hydro-sulphurct of ammonia gave a shamoy-yellow 

 precipitate. 



c. Tincture of gall nuts gave a deep-brown precipitate 

 inclining to blue, which after some time became blueish 

 gray, 



d. Caustic 



