142 
HOUSEHOLD BACTERIOLOGY 
Now, the cell—so runs the theory—finding itself 
deprived of its food, produces a new and increased 
amount of this food-seizing substance. In fact, in 
accordance with a well-known law in pathology, it 
produces such a surplus of this substance that it is 
cast off into the body fluid. 
But this food-seizing substance, now produced in 
superabundance and cast off, is still capable of uniting 
with the poison which is circulating in the body fluids. 
This it does, and as molecule by molecule the poison 
forms the new chemical union it is neutralized and 
so prevented from coming in contact with the cells, 
where alone it can do harm. This is antitoxic im¬ 
munity. 
Now, if more of this stuff is given off by the cells 
in the emergency than is necessary to render all the 
poison harmless, the excess in the body fluid remains 
there as unused antitoxin. This is the condition of 
the immuned horse. His cells have produced more 
antitoxin than is necessary to protect himself, and 
we draw off some of it in the blood and use it to 
save the child. 
Thus we see that this curious protective process 
is not an incredible anomaly, but that the body cells 
have availed themselves in an emergency as protective 
agencies of those capacities which under normal con¬ 
ditions they use in the assimilation of their food. 
This power of the body to protect itself against the 
poisonous products of bacterial life may be exerted 
