Sir H. Davy on a new Substance, &c, 75 
with the metals and with phosphorus and sulphur, and like- 
wise with the alkalies and metallic oxides, that it forms a de- 
tonating compound with ammonia, that it is soluble in alcohol, 
and still more soluble in ether; and that by its action upon 
phosphorus and upon hydrogen, a substance having the cha- 
racters of muriatic acid is formed. In this communication 
they offered no decided opinion respecting its nature. 
M. Ampere had the goodness to give me some of this sub- 
stance, and M. Clement having requested me to submit it to 
some analytical tests, I made several experiments upon it, 
which convinced me that it was a new substance undecom- 
• pounded in any of the circumstances to which I was able to 
expose it ; and that the acid formed in processes upon it was 
not muriatic acid, but a new acid possessing a striking resem- 
blance to that body. 
M. Gay Lussac (to whom M. Clement had furnished some 
of the substance, and with whom he had made some experi- 
ments upon it before the communication of his memoir) on 
Monday, Dec. 6, read to the Institute a paper, in which he 
stated that the acid formed by its action on hydrogen is a 
peculiar one. He mentioned several interesting particulars 
respecting the mode of its production, and he compared it to 
oxymuriatic gas or chlorine, and stated that two hypotheses 
might be formed on its nature ; and that it might be considered 
as an undecompounded substance, or as a compound of oxy- 
gen ; M. Gay Lussac is still engaged in experiments on this 
subject, and from his activity and great sagacity, a complete 
chemical history of it may be anticipated. But as the mode of 
procuring the substance is now known to the chemical world 
in general, and as the combinations and agencies of it offer an 
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