432 On the different Compounds formed by the 
impregnated with the same odour. The water which was 
boiled upon this substance was of a yellow colour and 
slightly acid, as appeared by the test of turnsole: with ba- 
rytes water, it formed a precipitate of vellow floccules en- 
tirely soluble in nitric acid. Although this substance was 
boiled in a very large proportion of water, the latter was 
always tinged ofa yellow colour. After being thus washed, 
it was subjected to the action of heat in a glass vessel; it 
melted, and there were obtained, among other products, 
nitrous vapour, nitrous gas, and a coal which had a sul- 
phureous smell. Although I only operated on ‘two deci- 
grammes of this substance, I am led to believe that it is 
composed of nitric acid, a small quantity of sulphuric acid, 
and of a carbonated matier more hydregenated than that 
which forms the coaly residuum*. 
The artificial production of a substance which possessed 
the odour of musk had already been observed by Geoffroy 
in 1726, and by Margraff in 1758{. The first discovered 
it upon nsixing sulphuric and nitric acids with clear oil of 
petroleum; the second, in mixing rectified oil of amber 
with uitric acid. IT myself have often had occasion to re- 
mark the same thing with the resinous substance which 
remains afier the inflammation of oil of turpentine with 
the sulphuric and nitric acids. It appears, that in all these 
instanees it is formed by the combination of nitric acid, and 
sometimes of sulphuric acid, with the oily matter. 
The results of the action of nitric acid upon the coaly 
residuum offer the following interesting facts to our con- 
sideration, 
1. They prove that the coaly residuum which contains 
sulphuric acid does not part with it upon being combined 
with nitric acid, (except the small quantity of it which is 
loose 3) and that, if we rely upon the test of barytes to de- 
monstrate the absence Of sulphuric acid, we shall be de- 
ceived, because the precipitate in which we should suspect 
the acid to be would be soluble in nitric acid. 
2. They confirm what I advanced in a former memoir, 
on the combination of sulphuric acid with the tanning mat- 
ter of pit-coal, which forms with barytes a compound so- 
Juble in nitric acid. ¢ 
3.*They shew that, by the re-action of nitric acid upon a 
coaly substance containing a great deal of hydrogen, a 
* Having by chance left a certain quantity of this substance exposed to 
the rays of the sun, Lobserved at the end of two morths that it was covered 
with small brilliant crystals. 
+ Memoirs of the Academy ‘of Sciences. $ Opuscules, tome ti. 
porlion 
