Re-aclion of Sulphuric Acid on Camphor. 497 
ionger any uncombined sulphurous acid in this coaly resi- 
duum, and that, if it contained any, it must have been ina 
state of close combination. : 
2. Action of Heat. 
T distilled four grammes of the coaly residuum in a small 
retort provided witha balloon, and obtained the following 
products; 1. a litle moisture; 2. sulphurous acid; 3. sul- 
phuretted hydrogen, part of which was decomposed by the 
sulphurous acid, and part remained in the balloon, although 
there was in it an excess of the acid; 4. a red oil, which 
became brown on exposure to the air, This product, some 
time after its distillation, gave out an aromatic sulphurous 
odour resembling that of amber and pyritous coal; satu- 
rated with potass, it gave out volatile alkali, but in too small 
a quantity to enable me to draw any inference from its pre- 
sence. ° 
I observed in another experiment, made over mercury 
in a very small apparatus, that it gaye out carbonic acid 
gas, oxy-carburetted hydrogen gas, sulphuretted hydrogen 
gas, and much less sulphurous acid than in the former 
distillation, which was made into a vessel containing a large 
quantity of atmospheric air. The action of heat proves, 
that besides carbon and hydrogen there are contained in the 
coaly residuum sulphur and oxygen, but it does not deter- 
mine whether these last exist in it in the state of sulphuric 
acid, or are immediately combined with the carbon and 
hydrogen. However, if we consider that the coaly resi- 
duum reddens turnsolg, the first opinion is the most pro- 
bable, and I adopt this as being the one most consistent with 
the facts and with analogy *. ; 
The matter remaining in the retort after the distillation 
of the remainder of the coaly substance was black, semi- 
fused, formed of small shining grains, and resembled coak ; 
it weighed two grammes and two deci-grammes. It was 
inodorous ; but, on being exposed to the air for some time 
on a plate of copper, it blackened that metal, and gave out 
a smell of sulphuretted hydrogen. This phenomenon in- 
duced me to make some experiments upon this substance, 
in order to ascertain in what state the sulphur existed in it. 
I boiled it in water, but this did not dissolve the least par- 
ticle of it; it caused no precipitate either with water of 
barytes, or with a solution of acetate of Jead. I boiled it 
* Yet it is not impossible but there may be in this compound a small 
guanuty of sulphur in a combustible state. 
scyeral 
