364 
carbon is always preceded by the motion of the 
blood, and must, therefore, be considered, like every 
other separation of matter from that fluid, as an ani- 
mal function, carried on and maintained by an ap- 
propriate organic structure, and according to the 
laws which regulate the exercise of living action ; 
while, in inanimate bodies, this carbon is yielded in 
the progress of those spontaneous changes which ulti- 
mately terminate in the dissolution of the animal 
compound. Between the termination of the living 
and the commencement of the dead process, a 
period, more or less long, appears to intervene ; and 
this period will vary, in different cases, according to 
the natural constitution of the body, and the mode 
and degree in which the external agents are employ- 
ed. If the body retain its susceptibility of action, 
these agents will restore its living functions ; if this 
susceptibility be lost, they only serve to hasten its 
decomposition and decay. Thus nearly do the 
powers required to exhibit the phenomena of life 
and of dissolution approximate each other ; and thus 
do two series of actions, in their effects and conse- 
quences so entirely distinct, proceed under the opera- 
tion of the same external agents. 
676. With respect to the actual place of union 
between the carbon and oxygen in living animals, 
we suppose it to happen at the surface of the re- 
spiratory organ, whatsoever be the form of the organ, 
or in whatever part of the body it be placed. By 
the motion of the animal fluids, which universally 
precedes this combination, the carbon is brought to 
r.his surface in a state fitted to combine, and the air. 
