On Respiration and Animal Heat 39 
aqueous vapour expired has been shewn and 
its source explained in a way contrary to his 
view:: But that arterial blood has a greater 
capacity for heat than venous blood, that, oxy- 
gen gas has a greater. capacity for heat than 
carbonic acid gas, the two great pillars on 
which his theory is supported, remain un- 
touched ; indeed his results in regard to these 
points are so plausible, and. his whole theory 
so beautiful, that one would feel a regret in 
having to question the accuracy of his prin- 
ciples. 
—_— 
On ihe gradual Deterioration of the Almo- 
sphere, by Respiration and Combustion. 
IT is now upwards of 20 years since Dr. 
Priestley published an Essay, “ On the Res- 
toration of air infected with Animal Respira- 
tion and Putrefaction, by Vegetation.”* After 
remarking that candles will bura only a cer- 
tain time, and animals live ‘only a certain 
time, in a giyen volume of atmospheric air 
the air being rendered noxious by those pro- 
cesses, he adds, “I do not know that any 
\ * Experiments and Observations payee vol 3, page 
« 25u. JOS DO i9'S4 J 
4 
