18 ANALYTIC . SECT. IL. 
are attended by some change of temperature ; it 
is therefore in unison with fair induction to infer, 
that decomposition is a source of animal heat.— 
But chemical combinations in the human body 
are themselves the consequences of the vital force. 
xx. It is impossible to completely destroy the 
vital force in an instant, by any violence, however 
severe. The bodies of those who die suddenly of 
apoplexy, or who are suffocated by gases, cool 
down to the common temperature of surrounding 
objects much slower than the corpses of those who 
die of lingering, or even acute, diseases. This 
difference in the cooling of dead bodies, can 
arise only from the generation of heat, after the 
cessation of breathing and pulsation. 
xxi. The quantity of caloric constantly escap- 
ing from the human body, is immense. An 
ordinary-sized man is calculated to inspire 100 
cubic feet of air in twenty-four hours; and if its 
temperature be 32°, it is raised to about 96° by the 
animal heat communicated to it during the act of 
respiration. About two pounds of water, in a 
state of vapour, pass off by pulmonary exhalation 
in twenty-four hours, which must absorb 900° of : 
caloric in assuming an aériform state. The insen- 
sible perspiration also abstracts no inconsiderable 
quantity of caloric. 
xxi. Some animal heat likewise goes off by 
radiation ; but from the comparative facility with 



