DS 
Gerlach attempted to make use of sheep and goats for reducing the 
virulence, but these experiments did not result in any true attenuation, 
for at a later date Koch, and Kolle and Turner showed that in the 
case of goats the lessening of virulence which might occur was of so 
incomplete a degree that no practical result was accomplished, while 
with sheep the virulence was, if anything, increased, 
If one can not obtain a naturally salted animal with which to com- 
mence operations, it is necessary so to produce the disease in one that 
it will recover spontaneously and therefore become artificially immune. 
Koch, in the course of his investigations in South Africa, discovered that he 
could accomplish this result by the injection of fresh bile, taken from an animal 
sick with rinderpest, into a well one. Later, he found that the blood of salted 
cattle would in some degree protect and that it might be used in combination 
with virulent blood with good results. Having recourse to these two methods, 
it was simply necessary to take a salted animal and by the injection of more 
virulent material gradually produce such a degree of immunity that the serum 
would be efficient in small doses. Theiler and Pitchford, Danysz and Bordet. 
Kolle and Turner, Nicolle and Adil-Bey, and others applied these methods with 
most excellent results. Kolle and Turner used gradually increasing amounts of 
virulent blood, injected at certain intervals beneath the skin of the cattle. Nicolle 
and Adil-Bey used the more rapid method of injecting 4 to 8 liters of virulent 
blood with 25 cubic centimeters of serum. 
Still another method, introduced by Yersin, is that of peritoneal lavage, but 
this has not been extensively employed. 
The method in use at the Serum Laboratory of the Bureau of 
Science.—In our work, the animals to be used for the production of 
antirinderpestic serum are first inoculated with this serum in amounts 
varying from 50 to 100 cubie centimeters. After an interval of a day 
or two, or sometimes perhaps after seven to ten days, they receive 
from 1 to 10 cubic centimeters of virulent blood: after this injection, 
others are given two weeks apart and in the following amounts: 50, 100, 
290, 500, and 1,000 cubic centimeters. The last injection having been 
given, three bleedings follow at each of which from 3,000 to 3,500 cubic 
centimeters of blood are drawn, and when this has been accomplished, 
1,500 cubic centimeters of virulent blood are once more injected. Ten 
days thereafter three additional bleedings are made and again virulent 
blood is used in a dose of 2,000 cubie centimeters to be followed. as in 
the other cases, by three bleedings. The same procedure obtains with 
the subsequent injections of 2,500, 3,000, and 3,500 cubic centimeters of 
virulent blood. A reaction, to be recognized by a rise in temperature, 
should result after each injection of virulent blood. 
Methods of producing immunity.—Generally speaking, there are three 
methods of securing an immunity to rinderpest, namely, the active, the 
passive, and the combined active and passive (Sobernheim). The active 
immunity is ordinarily of longer duration than the passive and in 
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