ficiency of the medical profession in dealing
with disease, by putting us on the track of imitating the methods which
the body itself uses for destroying, or checking the spread of, invading
germs and leading us to trust nature and try to work with her instead of
against her. Our antitoxins and anti-serums, which are our brightest
hope in therapeutics at present, are simply antidotes which are formed
in the blood of some healthy, vigorous animal against the bacillus whose
virulence we wish to neutralize, such as that of diphtheria or
septicemia.

Diphtheria antitoxin, for instance, the first and best known triumph of
the new medicine, is the antidotal substance formed in the blood of a
horse in response to a succession of increasing doses of the bacilli of
diphtheria. Similar antidotal substances are formed in the blood in all
other non-fatal cases of infectious diseases, such as typhoid,
pneumonia, blood-poisoning, etc.; and the point at which they have
accumulated in sufficient amounts to neutralize the poison of the
invading germs, forms the crisis, or "turn" of the disease. So that when
we speak of a disease "running its course," we mean continuing for such
length of time as the body needs to produce anti-bodies in sufficient
amounts to check it.

The principal obstacle to the securing of antitoxins like that of
diphtheria for all our infectious diseases is, that their germs form
their poison so slowly that it is difficult to collect it in sufficient
amounts to produce a strong concentrated antitoxin in the animal into
which it is injected. But the overcoming of this difficulty is probably
only a question of time.

Obviously, if infectious disease be, as we say, "self-limited," that is
to say, if the body will defeat the invaders with its own weapons, on an
average in nine cases out of ten, our wisest course, as physicians, is
to back up the body in its fight. This we now do in every possible way,
by careful feeding, by rest, by bathing, by an abundance of pure water
and fresh air, with the gratifying result that we have already reduced
the death-rate in most fevers, even such as we have no antitoxin
against, or may not even have discovered the causal germ of, to one-half
and even three-fourths of their former fatality. The recognition of the
fact that disease has a natural history, a birth, a term of natural
life and a death, has already turned a hopeless fight in the dark into a
victorious campaign in broad day