Vice-President’s Address. 133 
small doses of pure toxin. . It was also, however, found that, 
if an animal was injected with toxin and serum at the same 
or at different parts of the body, the animal survived doses 
of the toxin many times stronger than was necessary to 
produce a fatal effect when the toxin alone was used. To 
many this action of the serum appeared to be exercised 
directly on the poison, and to be probably of a chemical 
nature, either destroying it or converting it into a harmless 
substance. To this property, or rather to the substance in 
the blood which exercised this striking influence, the name 
Antitoxin was given, and its action has been compared to 
that of a globulin or a diastase. In the two diseases 
mentioned, the quantity of serum. containing the antitoxin 
necessary to prevent death is almost infinitesimal, it being 
calculated that one c.c. is sufficient to protect 70,000 mice 
against what would otherwise be a fatal dose. 
Although this antitoxic action appears to be so marked in 
the two examples referred to, it is not a property which is 
found so generally existing in analogous cases as to permit 
its being formulated into a universal law. In the investi- 
gation of other diseases produced by microbes, and occurring 
in animals, it has been found, on the contrary, that the serum 
of vaccinated animals is able to prevent or cure the disease, 
while at the same time it possesses no true bactericide or 
antitoxic property. From these latter observations it is 
necessary to seek some other explanation of the curative 
or preventive action of the serum, to which it will be 
necessary to refer more fully afterwards. 
These investigations show very clearly that the serum of 
blood is very far from being an inert constituent. Some 
further facts in this connection have some bearing upon the 
understanding of our subject. If, for example, the blood of 
another species is introduced into the body, or even mixed 
with the blood-serum, the blood-corpuscles are disintegrated 
and dissolved. This action of the serum is known as its 
globulicide action. 
Another fact in this connection is that blood-serum in 
quantity, taken from one species of animal and injected into 
another, may produce symptoms of marked intoxication, 
