SECT. Il. PHYSIOLOGY. 5 
SECTION II. 
Animal Heat. 
1. Tue faculty of generating a constant supply V 
of caloric, is a property peculiar to living’ 
organized bodies; some have also alleged its 
existence even in vegetable life, during the spring 
and summer. Animal heat is too remarkable a 
phenomenon to have escaped the scrutinizing spirit 
of the Greeks: they distinguished two sources of 
it in the animal economy, the ‘ugurov Guo, or 
innate heat, and the cvuguror bpuov, or connate heat. 
The connate heat they conceived to be a portion 
of the semen, or blood of the mother, forming 
the substance of all our organs, and belonging to 
- the hot and dry elements. The innate heat they 
thought to be a nobler substance than the 
elements, being of a divine nature, and having its 
seat in the heart. This theory of animal heat 
prevailed to the time of Willis, who affirmed, 
that the heart communicates even incandescent 
particles (scintillas) to the blood in its passage 
through the ventricles. 
u. Towards the close of the 17th century, the 
pneumatic theory of animal heat began to obtain 
