428 On the different Compounds formed ly the 
several hours in a solution of potass, and the result was tire 
same. 
Not being able by these methods to detect the presence 
of sulphur in this substance, I thought of detonating it with — 
nitrate of potass. The residuum of the detonation, dis- 
solved in water, filtered and supersaturated ‘with nitric acid, 
afforded by the addition of nitrate of barytes an abundant 
precipitate of the sulphate. ‘hese experiments show that 
sulphur may be so intimately combined with carbon as to 
resist the action of a red heat, and of liquid potass. We 
cannot admit the presence of sulphuric acid in this com+ 
bination ; for all the known facts prove that the compounds 
in which this acid is the most concentrated do not resist, 
at a high temperature, the affinities of carbon and hydrogen, 
If oxygen at all exist in this combination, it can only be 
in avery small proportion, since it does not by heat act 
upon the combustible substances, so as to form with them 
gaseous products. From all these considerations, it appears 
to me, that we ought to regard the matter remaining after 
the distillation of the coaly residuum as a combination of 
carbon, sulphur, and a small quantity of hydrogen. 
The solid combination of carbon and sulphur is not a 
fact entirely unknown to chemists. MM. Clément aud 
Desormes have spoken of it in their Memoir upon Carbon; 
since which time M,. Amédée Berthollet bas shown, that 
by passing sulphur in a state of vapour over charcoal, a cer- 
tain portion of the sulphur becomes fixed in it. |» The ana- 
lysis of gunpowder vields the same combination. When 
the nitrate of potass has been carricd. off by means of water, 
the residuum, which is not soluble, and which consists of 
charcoal and sulphur, parts but with a very small quantity 
of this latter, by the action of heat; and to this is owing 
the sulphuric acid that is formed when the residuum already 
heated in a close crucible comes to be burned. ‘These in- 
teresting facts on the analysis of gunpowder were commu. 
nicated tome by M. Proust, when I gave him an account 
of my labours. 
M. Proust, much strnck with the odour of sulphurous 
acid generally exhaled from pit-coals’ towards the end of 
their combustion, thought at first that the sulphur in them 
had formed with the carbon a combination analogous to 
what I have deseribed’; but having afterwards observed that 
these coals plunged into nitric acid burned to the last with- 
out exhaling the least odour of sulphurous acid, he at 
Jength coneluded that the sulphur was not combined with 
carbon, but with iron. I mention thts fact, because it ap- 
pears 
