THE PRODUCTION OF IMMUNITY. 
527 
with absolute alcohol does not suffice to destroy the germs, 
and it is necessary to free the solution from germs by means 
of a Pasteur filter, or in some other suitable way. Therefore 
experiments made with material which has not been tested for 
germs are practically of no value. As to the poisonous char¬ 
acter of the ptomaines, a single large dose is sufficient to kill 
a guinea-pig in from one hour to two days. The autopsy of a 
case of this kind is as follows: Liver, pale and fatty; subcu¬ 
taneous tissue over abdomen, necrosed and infiltrated ; muscle 
soft and friable. Other organs apparently normal. 
The experiments here recorded show : 
1. That in guinea-pigs complete immunity {com hog-cholera 
can be produced by chemical inoculation. 
2. The suchlotoxins and sucholo-albumin are equally effec¬ 
tive in this respect, and a mixture of these two products gives 
greater immunity than either used by itself. The effect of the 
albumin in producing immunity from anthrax has already 
been pointed out by Hankin, his experiments being very suc¬ 
cessful. 
3. The sucholotoxins given in large doses produce death. 
To produce immunity they should be administered in small 
quantities at a time and at frequent intervals, the system being 
in this way accustomed to the poison and enabled to resist it. 
Further study in this interesting line of work is in prog¬ 
ress. 
The tabulated results of the foregoing experiments are 
appended: 
