072 
ROBERT H. WILSON. 
A product consisting of the protective and immunizing prop¬ 
erties of the anthrax bacteria, but the organisms themselves being 
destroyed, is on the market. It is much safer to use than the 
Pasteur vaccine and the results obtained from its application seem 
to be quite satisfactory. This preparation is put up in pellet form 
and is easily and conveniently applied. 
Blackleg Vaccine. This vaccine, which consists of the at¬ 
tenuated blackleg organisms, may be a single vaccine conferring 
immunity by one inoculation or a double vaccine, which requires 
two inoculations to produce successful results. The strength of 
the single vaccine is about half way between that of the first and 
second of the double. 
The product is prepared from the affected muscle tissue of 
animals dead from the disease. The muscular tissue containing 
the organisms is thoroughly dried and ground to a powder. 
Usually a sufficient amount of sterile water is added to the powder 
to produce a paste of the consistency of soft putty. The material 
is then subjected to a temperature of from 90 to 100 degrees for 
six or eight hours. The degree of heat used in the preparation 
of the vaccines is used as a basis for differentiating them into 
single and double vaccines. 
Both single and double vaccines are marketed in the powder 
or oid or pellet form, the latter having been first suggested by 
Houghton in 1898. There is practically no difference in the 
efficiency of the powder and oil forms; the oil form, however, 
seems to he more popular, as it is convenient to administer and 
assures accuracy of dosage. The double vaccination is rec¬ 
ognized as giving a greater degree of protection, and it is espe¬ 
cially recommended for pure bred stock and animals in poor phys¬ 
ical condition. The vaccine is injected subcutaneously, any region 
being used, the neck, tail, ear or brisket. It is of course quite 
essential to disinfect the site of the injection, also to have the 
needles and syringes as nearly sterile as possible. 
The duration of immunity produced by the vaccine is of vary¬ 
ing length. The younger the animal the shorter seems to be the 
period of immunity. Calves under a year old should be vac- 
