413 On some new 'Electrochemical Researches 



live surface, in contact with solid potash, an alloy of arsenic 

 and potassium was formed of a daik gray colour, and per- 

 fectly metallic ; it gave off arseniuretted hydrogen by the 

 action of water with inflammation, and deposited a brown 

 powder. 



When potassium and arssenic * were heated together in 

 hydrogen gas, they combined with such violence as to pro- 

 duce the phaenomena of inflammation, and an alloy was 

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

 Voltaic battery. 



As tellurium and arsenic both combine with hydrogen, 

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

 potassium, with tellurium and arsenic, upon ammonia, 

 some new phsenomena would be obtained, and probably, 

 .still further proofs of the decomposition of the volatile al- 

 kali, in this process afforded ; and this T found was actually 

 the case. 



When the easily fusible alloy of tellurium with potas- 

 sium, in small quantity, was heated in ammonia, the sur- 

 face lost its metallic splendour, and a dark brown matter 

 was formed, 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 

 hydrogen, as in the case of the action of potassium alone. 



The alloy of arsenic and potassium, by its action upon 

 ammonia, likewise produced a gas which was principally 

 nitrogeA ; so that if it be said that the metai, and not the 

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

 must be considered in some cases as a compound of nitro- 

 gen, and in others a compound of hydrogen ; which are 

 contradictory assumptions. 



None of the chemists who have speculated upon the 

 imaginary hydrogenation of potash, as far as my know- 

 ledge extends, have brought forward any arguments of 

 analysis, or synthesis. Their reasonings have been found- 

 ed, either upon distant analogies, or upon experiments in 



♦ In reasoning upon the curious experiment of Cndet, of the production of 

 a volatile pvrophorusby the distillation of acetite of porash, and white oxide 

 of arsenic, FourcroyConnais Chem. torn viii. p. 197,1 C(^nceivcd it probable, 

 that this pyrophorus was a volatile alloy of potassium .iiid arsenic. But 

 from a repetition of the process I find, that though potash is decompounded 

 in this operation, yet that the volatile substance is not an alloy ot potassium, 

 but contains charcoal and arsenic, probably with hydrogen. The galses 

 not absorbable by water given ofF in this operation, are peculiar. 1 heir 

 smell is intensely foetid. They are inflammable, and seem to contain char- 

 coal, arsenic, and hydrogen: whether ihey are mixtures of various gases, 

 or a single compound, I am not at present able to decide. 



which 



