82 On Respiration and Animal Heat 
has burned out, I am almost convinced that 
the changes effected by these processes are 
the same; and consequently am inclined to 
believe that all the oxygen, which disappears 
im the Inng’s, goes to form the carbonic acid 
produced, whilst the heat liberated enters the 
blood for the purpose of preserving the tem- 
perature of the body. 
But it will be said, there is more oxygen 
spent than is requisite for the carbonic acid ; 
what then becomes of the surplus ? In answer 
to this I would observe, that the fact stated 
in the objection must first be ascertained.— 
According to Lavoisier, whose results have 
been since corroborated by those of Clement 
and Desorme, 28 parts of charcoal, by weight, 
unite with 72 of oxygen, to form carbonic 
acid; in this case, a given volume of carbonic 
acid contains almost exactly the hke volume 
of oxygenous gas; whence the objection would 
have validity. But Crawford, (page 343) 
finds 20 of charcoal unite to 80 of oxygen 
to form carbonic acid; in this case, 4 mea- 
sures of carbonic acid will be found to con- 
tain 4,68 measures of oxygenous gas, or 6 
contains 7 nearly; and the proportion will 
come very near to that observed as the effect 
of respiration; the difference is so small as 
may easily be attributed to imaccuracies, even 
in the present improved state of Hudiometry. 
