NEW METHOD OF ANALYSIS. 
45 
means of sulphuric acid; but here, also, the inequality of 
the results caused me to renounce this mode. 
I was rather more successful when I employed the oxide 
of mercury, for, besides the advantage of more easily con- 
suming the organic matter, I found this, likewise — the estima- 
tion of the quantity of oxygen furnished by the combustion. 
This success not being sufficient to satisfy me, I continued 
my researches, and was not long in obtaining results which 
astonished me by their exactness, by employing the sulphate 
of mercury, which, besides the property it had of consuming 
the organic matters at a low temperature, afforded, moreover, 
in the products of its decomposition by the hydrogen and 
carbon, many means to verify the composition of the organic- 
matters. Thus, in causing two volumes of hydrogen to act on 
the sulphate of mercury, there was liberated but one volume 
of sulphurous acid, because, as I convinced myself, the reduc- 
tion of the acid and the base took place simultaneously; and 
two volumes of hydrogen absorbing but one of oxygen, it 
follows that there could have been but a half volume of oxygen 
taken from the sulphuric acid, and, consequently, but one 
volume of sulphurous acid disengaged. One atom of carbon 
requiring two atoms of oxygen for its conversion into car- 
bonic acid, and acting simultaneously with the hydrogen 
upon the base and acid, would take from the sulphuric acid 
one volume of oxygen, and liberate two volumes of sulphurous 
acid; that is to say, a quantity equal to that of the carbonic 
acid. 
From the facts, we may make the following deductions : 
1. That from every organic substance, which consists of 
carbon, together with oxygen and hydrogen in the proportion 
to form water, there will be disengaged equal volumes of car- 
bonic and sulphurous acids. 
2. That from a substance formed of carbon and oxygen, 
earbonic and sulphuric acids will be produced ; that the 
volume of the first will exceed that of the sulphurous acid ; 
and, finally, that the difference will represent the volume of 
oxygen which exists in the matter. 
