82 PATHOGENIC BACTERIA.

the body-cells or bactericidal body-juices to properly cope
with them, so that they develop and engender the poison-
ous substances which are the essential factors of disease-
production. The more the body and its component ele-
ments are injured, the more successful the inroads of the
bacteria, the more prolific the toxin-production, and the
more severe the affection.

The presence of the antitoxin annuls the poison, main-
tains the vitality of the organism as a whole, sustains
the integrity of its tissues, and so places the pathogenic
bacterium on a very different footing in relation to the
organism.

An antitoxin is a neutralizing or annulling agent, not
a regenerating one, and therefore in therapeutics finds
its proper sphere only in the beginning of the disease
combated. Up to a certain point the symptoms of diph-
theria and tetanus are due to the circulation of toxins in
the blood, and can be successfully combated by antitoxic
neutralization. Later in both diseases we have symp-
toms resulting from disorganization of the nervous sys-
tem, degeneration of the heart-muscle, destruction of the
kidneys, etc., and the neutralization of the poison can be
of no avail because the lesions are irreparable, and the
patient must succumb.

I have used the term " neutralization," in speaking of
the antitoxins, in a rather free and scarcely warranted
manner, and must call attention to the fact that their
operation is probably not exactly analogous to chemical
neutralization. From mixtures of toxin and antitoxin
the unchanged poison has been recovered. The effect of
an antitoxin may be a biologic one, by which the tissues
are so stimulated as to endue the action of a substance
ordinarily disorganizing in effect.

Buchner and Roux have both pointed out that when the
toxins and antitoxins are mixed and introduced into ani-
mals of greater susceptibility than are ordinarily used, the
presence of an unaltered toxin can easily be demonstrated.
This proof is, however, of very little value, for let the