8 ANALYTIC SECT. II. 
time, the generation of animal heat by respiration. 
Thus, according to him, atmospheric air contains a 
much greater quantity of specific caloric than car- 
bonic acid gas; and the oxygen of the atmospheric 
air taken into the lungs being changed into car- 
bonic acid, a disengagement of caloric equal to the 
difference of their capacity for it, should happen 
during every inspiration. But the capacity of 
arterial blood for caloric being 1.0300, and that of 
venal only .8928; the heat generated by the 
formation of carbonic acid in the lungs, he sup- 
posed to be absorbed in a latent state, by the arterial 
blood which again disengaged it, in a free state, 
in its transition through the capillary vessels. 
v. The opinions of Priestley and Crawford were 
no sooner published in England, than Lavoisier and 
the Marquess La Place undertook the investiga- 
tion of the same subject. 'They placed guinea-pigs 
in a calorimeter, and kept them in it for several 
hours; they then estimated the quantity of ice 
melted, and of carbonic acid formed, during their 
stay in the calorimeter. They afterwards formed 
an equal quantity of carbonic acid by combustion 
in the calorimeter, and found that nearly the same 
quantity of ice had been melted by the guinea- 
pigs while they remained in the calorimeter, as by 
the process of combustion in the last experiment: 
vi. The pneumatic theory of animal heat was 
thus apparently proved analytically and syntheti= 
