86 * 
Sir H. Davy o?i a new Substance 
potassium, but likewise enough to decompose a portion of 
muriatic acid, sufficient to afford chlorine to enter into combi- 
nation with the whole of the substance. 
When the binary compound is used, the result is a simple 
instance of double affinity ; the new substance quits the potas- 
sium to unite to the hydrogen of the muriatic acid, and the 
chlorine and the potassium combine : and that the decompo- 
sition is only partial depends probably upon the attraction of 
the compound of iodine and potassium for water. When mix- 
tures of the compounds are used, the oxygen is employed to 
attract hydrogen from the substance, to which it seems to 
adhere with a much weaker attraction than to chlorine. 
M. M. Desormes and Clement have mentioned, that when 
the new substance is exposed to liquid ammonia, a black pow- 
der is formed, which, when dry, fulminates by the slightest 
contact or friction. I introduced some of the substance into 
solution of ammonia, and separated the liquor from the black 
powder, and evaporated it to dryness ; it left a white saline 
substance, the same as that produced by the union of ammonia 
with the peculiar acid, which consists of the substance com- 
bined with hydrogen ; and hence it appeared probable that 
a portion of ammonia had been decomposed to furnish hy- 
I made the experiment on the action of strong solution of 
ammonia on the substance in a pneumatic apparatus ; but no 
azote was given off. Hence I am induced to conclude, that 
the black powder is a compound of the new substance and 
azote, similar in its character of a binary compound to the 
detonating oil discovered by M. Dulong; and this conclusion 
is strengthened by the results of its detonation in a tube 
of glass partially exhausted: they are, I find, the peculiar 
