1889 - 90 .] Dr G. E. C. Wood on Enzyme Action. 
41 
to external injurious agencies in proportion to the degree of attenu- 
ation they had undergone. The incapacity of the vaccines to grow 
and cause disease in the bodies of susceptible animals he ascribed 
to their lessened reproductive power and greater sensitiveness, which 
gave the victory to the animal in the struggle for mastery. He saw 
no reason to suppose that the action of these microbes depended in 
any degree on the production of specific toxines. As his experiments 
were carried out in greatest detail on anthrax, I will limit myself at 
present to its consideration. On comparing the action of the virulent 
organism and its vaccines on Koch’s gelatine, the vaccines were seen 
to liquefy the gelatine much more slowly, and had in fact lost in 
great part their enzyme function. This effect was much more 
clearly shown in milk. The normal anthrax coagulated the milk 
on the second day, while Pasteur’s 1st vaccine only began to show 
signs of this after, at earliest, two weeks. My suggestion that the 
phenomena were in great part to he accounted for by interference 
with enzyme function was confirmed by this result. The method 
by which Fliigge compared the resistance of the organisms to acids 
was, shortly, as follows : — A series of test tubes, each containing the 
same quantity of gelatine, was prepared, and to each set a given 
number of drops of the acid to be tested was added. The organisms 
were then inoculated by means of a platinum wire in a set of 
tubes containing the same quantity of acid, and their growth com- 
pared. I was able, however, to register more exactly the effect of 
the acidity by the following modification. The acid gelatine was 
rendered fluid, and after being inoculated was, as it cooled down, 
distributed uniformly on the walls of the tube. By this means the 
organism was enveloped on all sides by the medium whose influence 
was to be tested. In addition, as the organisms became separated 
from one another in the liquefied gelatine, the colonies which ap- 
peared later would each originate approximately from one organism, 
and thus the disturbing influence arising from the varying quantity 
introduced in each case was eliminated. I was, by this method, 
able to confirm Pliigge’s statement, that the vaccines were much 
more easily inhibited in their growth than the unaffected organism. 
A new tube was now added to each set, and inoculated with virulent 
anthrax which had been grown for some time anaerobiotically. The 
anaerobe organism was found to be more sensitive than the vaccines , 
