676 
ROBERT H. WILSON. 
istering tetanus antitoxin. The immunizing dose of this product 
is about 1,500 units. 
Good results have been obtained with the antitoxin in many 
cases as a curative for the disease, especially in mild cases. As 
a curative it is given in larger doses and repeated, each dose con¬ 
taining at least 3,000 units given every three or four hours until 
the symptoms show abatement. 
The immunity produced by tetanus antitoxin is of course of a 
temporary nature. 
Influenza Antitoxin. The so-called influenza antitoxin, which 
consists of the serum of an animal recovered from an attack of 
influenza, has, according to many practitioners, given excellent 
results in immunizing against influenza and kindred affections. 
Antistreptococcic Serum. This is serum from a horse which 
has been immunized to killed cultures of the streptococcus organ¬ 
isms. Frequently several different strains of the organism are 
used. It has given fairly good results in many cases of strep¬ 
tococcus infection. 
Antihog Cholera Serum. This product devised by Dorset and 
Niles is at present probably the most reliable biological product 
for combating hog cholera. Hogs which are immune to cholera 
either through natural immunity or artificial immunization, are 
used in the preparation of the serum. These hogs are hyperim- 
munized by the injection of a large amount of the hog cholera 
virus. The intravenous method of injecting the virus seems to 
produce a more potent serum with a smaller amount of virus than 
is the case with either the subcutaneous or intraperitoneal method. 
About ten or fiteen days after receiving the virus the animals are 
bled from the tail, each succeeding bleeding being at intervals of 
a week. The blood is defibrinated and tested for potency. This 
defibrinated blood constitutes the hog cholera hyperimmune 
serum. 
There are two methods of administering the serum in the 
field, one known as the “ serum alone method ” and the other 
the “ simultaneous method.” In the former method the serum 
alone without anv virus is injected. This method produces a 
