
THE PRINCIPLE OF VITAL AFFINITY. — 339 
ultimate object, through the liver, answers the important purpose of equalizing 
the quantity of matter in the blood, which is always ready for this calorific union 
with oxygen. 
This doctrine, as to the chief use of the animal matter of the bile, appears to 
correspond perfectly with several known and important facts. When the quan- 
tity of bile thrown off by the liver, and discharged by the bowels, is decidedly 
greater than usual, the animal heat is remarkably depressed, as in cholera, appa- 
rently because the quantity reabsorbed and applied to the evolution of heat, is 
diminished. In herbivorous animals, the quantity of bile discharged from the 
bowels is much greater than in the carnivorous, because the quantity of amy- 
laceous matter which they consume is so much greater, that a much larger quan- 
tity is secreted, and if all reabsorbed into the blood, it would cause a morbid in- 
crease of heat. Again, in warm climates and seasons, the formation of bile is 
apparently stimulated, the liver is excited to increased action, and there is such 
an increase of the discharge by the bowels, as serves to lessen the quantity of 
combustible matter in the blood, and keep down the temperature of the body ; 
but then this increased stimulation of the liver renders it more liable to various 
forms of disease. 
When we say that oxygen, acting on the redundant, on the non-azotised, and 
on the effete matters with which it meets in the blood, is the main agent in form- 
ing the excretions, and causing the waste of the body, we use language which is, 
toa certain degree, ambiguous. It seems to me that the oxygen is probably capable 
of acting on all the matters in the blood for which there is no strong vital 
affinity in the body; and that the action of the oxygen on the matters which 
are ready to be, or have been, absorbed from the textures, is rather the con- 
sequence, than the cause, of their having lost their vital properties, and thereby 
come under the dominion of ordinary chemical affinities. The oxygen is, no 
doubt, the agent by which the gradual extenuation of the body, in death by 
famine, or by many lingering diseases, is effected, but this agency of the oxygen 
is in itself salutary, and even necessary to life; the real cause of death is, that 
cause which prevents the loss of substance effected by the oxygen from being im- 
mediately repaired, 7. ¢., it is the deficiency of nourishment, to take the place of 
those portions of the textures which have lost their vital properties, and therefore 
come under the dominion of the oxygen. 
This seems to be confirmed by the fact which appears to have been fully as- 
certained by CuossatT, that the rate of waste, 2. ¢., the rapidity of absorption of 
the textures of the body, is greatest shortly before death, 7. ¢., when the supply 
of the oxygen must be diminished, rather than increased, from the state of the 
circulation and respiration,— but when the vital powers, and especially the vital 
affinities, are losing their power, and the supply of nourishing matter has ceased. 
This fact alone seems sufficient to shew that the absorption. which is constantly 
