EXPERIMENTS ON THE METALS FROM THE' FIXED ALKALIS. 335 



drogcn gas, they combined with such violence, as to pro- arsenic heated 

 duce the phenomena of inflammation, and an alloy was pro- 111 kidrogeugas. 

 duced of the same kind as that formed by means of the 

 voltaic battery. 



As tellurium and arsenic both combine with hidrogen, 

 it appeared to me probable, that, by the action of alloys 

 of potassium with tellurium and arsenic upon ammonia, 

 some new phenomena would be obtained, and probably 

 still farther proofs of the decomposition of the volatile 

 alkali, in this process afforded • and this I found was actually 

 the case. 



When the easily fusible alloy of tellurium with potassium, Action of alio* 

 in small quantity, was heated in ammonia, the surface lost its potassiumoa" 

 metallic splendour, and a dark brown matter was formed, ammonia, 

 which gave ammonia by exposure to air ; and the elastic 

 fluid, which was generated, in this operation, consisted of 

 four sixths nitrogen, instead of being pure hidrogen, as in the 

 case of the action of potassium alone. 



The alloy of arsenic and potassium, by its action upon Action of alloy 

 ammonia, likewise produced a gas, which was principally potassium oa 

 nitrogen, so that if it be said that the metal, and not theammouisu 

 volatile alkali, is decomposed in processes of this kind, it 

 must be considered in some cases as a compound of nitrogen, 

 and in others a compound of hidrogen, which are contra- 

 dictory assumptions. 



None of the chemists, who have speculated upon the tma- Hidrogenatk>a 

 srinary hidrosrenation of potash, as far as my knowledge ex- of P otasri not 

 * A u I w* i it i • proved by ana- 



tends, have brought forward any arguments of analysis, or lysis or synthe- 



synthesis. ^Their reasonings hare been founded, either upon sis * 



potash and white oxide of arsenic, Foureroy, Connais. Chem. Tom. oxide of arsenic 

 viii, p. 197, I conceived it probable, that this pyrophorus was a aud ac «tate of 

 volatile alloy of potassium and arsenic. But from a repetition of pota> ' 

 the process I find, that, though potash is decomposed in this ope- 

 ration, yet the volatile substance is not an alloy of potassium, 

 but contains charcoal and arsenic, probably with hidrogen. The 

 gasses not absorbable by water, given off in this operation, are pe- 

 culiar. Their smell is intensely foetid. They are inflammable, and 

 seem to contain charcoal, arsenic, and hidrogen : whether they are 

 mixtures of various gasses, or a sittgle compound, I am not at present 

 able to decide, 



distant 



