DEPARTMENT OF AGRICULTURE. 
the use of Pasteur anthrax vaccine to three months from the date of 
its preparation. 
The injection of an inert product into animals would impart to 
the stock owners and veterinarians who employ it a false sense of 
security and would bring this method of vaccination into disrepute. 
At times no doubt great losses have resulted from the application 
of inert vaccines. 
Other disadvantages of the Pasteur method which must be con- 
sidered are, first, that it requires two handlings of the animals 
before immunity is established; second, that the losses from vac- 
cinations are not insignificant; third, that its standardization is 
not carried out very accurately ; and, fourth, that its administration 
in herds where the disease has already made its appearance is liable 
to induce the disease, through the reduction of the resistance of the 
animal during the process of vaccination, and for this last reason it 
is best adapted for use only with herds in which the disease has not 
yet appeared. 
These deficiencies of the method have been recognized by many 
investigators, who have endeavored to devise other methods of 
vaccination, and particular attention has been directed toward the 
preparation of a spore vaccine, because of its superior keeping 
qualities. In Russia at the present time the method of Zenkowsky, 
and in Hungary a spore vaccine prepared by Detre, are being suc- 
cessfully employed; although, aside from their keeping qualities, 
these products have all the other disadvantages of the Pasteur 
method. Successful vaccination by spore vaccines was also demon- 
strated by Nitta, in Japan, and by others. Other means of vaccina- 
tion with attenuated living cultures, aggressions, dead bacteria, etc., 
were tried, but proved of no advantage. 
Sclavo, Sobernheim, and others have established that injections 
of increasing amounts of virulent cultures into immune animals 
produced a serum which has great protective value against anthrax. 
Such protective serum may be produced in the various susceptible 
animals. 
PRODUCTION OF SERUM. 
The animals which are selected for the preparation of serum are 
subjected to a preliminary treatment either by sero- vaccination or by 
Pasteur's method, then at certain regular intervals they are infected 
with increasing doses of virulent anthrax cultures. For this purpose 
they receive in about 10 to 14 days following the preliminary treat- 
ment an injection of from 0.005 to 0.001 of a loopful of virulent cul- 
ture. In sheep it is advisable to exercise greater care, especially at 
