The average quantity of food required to sustain an ordinary man in
health and strength, I have previously stated, is about two pounds
avoirdupois daily, and an equal weight of oxygen is necessary to the
integrity of the vitalizing processes undergone by the food, and to
maintain the physical temperature. When the requisite supply of oxygen
is reduced, the extrication of heat within the system is promptly
diminished, but the vitalization of digested food is unfavorably
affected much more slowly, but with equal certainty. If the quota of
oxygen existing in the arterial blood of the vessels whose duty it is
to supply the vital fluid to the absorbent system, be inadequate to
enable these operations to go on properly, the life-giving processes
must necessarily be imperfectly accomplished. Under these
circumstances the digested material is imperfectly vitalized, and is
therefore inadequately fitted to be used in building up and repairing
the living body. But its course in the system cannot be delayed, much
less stopped.

The blood possesses a definite constitution, which cannot be
materially altered without the rapid development of grave, perhaps
fatal consequences. The nutritive matters received into the blood must
be given up by it to the tissues for their repair, whether such
materials are well or ill fitted for the vital purposes. Dr. B.W.
Carpenter, of London, the celebrated physiologist, makes the following
pertinent statements on this subject, which I condense from his great
work on physiology: "We frequently find an imperfectly organizable
product, known by the designation of tubercular matter, taking the
place of the normal elements of tissue, both in the ordinary process
of nutrition, and still more when inflammation is set up.