42 = British Association for the Advancement of Science. 
we had not the slightest doubt that urea, xanthic oxide, cystic 
oxide, oxalic acid, (which last substance is well known to consti- 
tute hemaets an ingredient in unary calculi, )—that all these bo- 
ies are produced by the decomposition of one single substance, 
and that substance uric acid. 
Our analytical investigations of these various bodies have not 
yet made sufficient progress to enable me to communicate them 
here. My intention at present is, to point out the plan which we 
followed in our attempts to decompose uric acid into its proximate 
elements, and the singular results which we obtained. But, be- 
fore proceeding to do so, I should like to notice a very remarka- 
ble compound, which will, I think, serve greatly to illustrate the 
subject we are at present occupied with. 
Winkler found, that when the distilled water of bitter almonds 
was mixed with muriatic acid, a new acid is obtained. The dis- 
tilled water of bitter almonds, in a pure state, contains nothing 
but prussic acid and oil of bitter almonds, (hydret of benzoyl.) 
When treated with muriatic acid, we obtain sal ammoniac and 
the new acid, and nothing else. It is evident from this, and the 
conclusion is corroborated by the ultimate analysis of the new acid, 
that the hydro-cyanic acid of the liquid is decomposed by the action 
of the muriatic acid into ammonia and formic acid ; that the am- 
monia combines with the muriatic acid, and that the formic acid, 
in the nascent state, unites with the oil of bitter almonds, to form 
a compound acid, in which the power of saturation of the formic 
acid is not changed. This acid performs, in every respect, the 
part of asimple acid ; and its existence has rendered probable the 
supposition, that the same views respecting other acids are not 
without foundation. Another interesting fact respecting this acid 
is, that when heated with hyperoxides, it is decomposed in a par- 
ticular manner, only one of its proximate constituents being oxi- 
dized, while the other suffers no change. The products obtained 
are carbonic acid and oil of bitter almonds. 
Now, I think it must be evident to every one, that uric acid 
must possess a composition similar to that of the acid just men- 
tioned ; and, therefore, that its oxidation in the same manner 
would, i in all probability, lead to interesting results. We obtain- 
ed, in fact, results which corresponded to our expectations. Uric 
acid may be considered as a compound of urea, with a peculiar 
t is, we may view it as an; c to nitrate of urea. 
