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animals which have recovered from the natural disease, it is apparently 
permanent. 
The methods in use for producing active immunity are also three in 
number. 
I. Koch’s bile method.—According to the results of Koch’s experiments in South 
Africa, 10 cubic centimeters of bile taken from an animal on the sixth to the 
eighth day of the disease will, upon injection into a non-immune one, confer an 
immunity which will persist for several months. The bile to be used must be 
clean, greenish and frothy, and must be unmixed with blood; however, in follow- 
ing this method the immunity is not demonstrable until about the tenth day after 
the inoculation. Rogers, in order to render any bile from a rinderpest animal 
available, has advocated its filtration, which would remove all organisms contained 
in the fluid; however, Kolle and Turner have demonstrated that this method 
could not be satisfactory, because, in order to produce an active immunity, the 
organisms of rinderpest should be present in the filtrate. The bile method is 
said to produce an active immunity (Kolle), and it is maintained that the 
organisms present therein are virulent, but that they are accompanied by sub- 
stances which hinder their spread in the animal inoculated. The same results 
can not be obtained with virulent blood and normal bile. Not all investigators 
have had as favorable results as Koch; those of Lingard and Rogers, for instance, 
were negative, but this was possibly due to racial differences in the cattle. Inocu- 
lation with bile has no value as a curative method. 
The advantages of this method are that no reactionary fever, suppres- 
sion of lactation, or abortions are produced and that the operations can 
be carried on in the field. The disadvantages are that immunity is not 
established until the tenth day after inoculation, that the latter is not 
permanent (four months, Haedicke), that a sufficient quantity of bile 
may not be obtainable and that it is difficult to preserve, although per- 
haps the observations of Nicolle and Adil-Bey, that bile desiccated in 
the presence of sulphuric acid will keep indefinitely, may be confirmed. 
II. Hohlstock’s modification of Koch’s method which consists in giving the bile 
inoculation a second time and then injecting virulent blood from ten to thirty 
days thereafter has not found much favor, since Kolle and Turner have shown 
that there was no appreciable increase in the immunity conferred by this method. 
[1]. Edington’s Glycerinated Bile Method, although it has found favor in some 
places, has been condemned by Kolle and Turner on the ground that the glycerine 
destroys the virus, and Hutcheon and Rogers state’ that only a short passive 
immunity is conferred. 
idington’s procedure was to take clean bile after the sixth day of the disease, 
and dilute it with an equal amount of glycerine; it should then be set aside for 
eight days. Edington used 15 to 50 cubic centimeters injected into the dewlap, 
and followed this by a small amount of virulent blood (0.1 to 0.2 cubic centimeter ) 
two days thereafter (ten days later, Nocard and Leclainche). Rogers thought 
that even foul bile might be used, since glycerine would destroy the organisms 
present therein. 
The advantages claimed for Edington’s method were that a long im- 
munity was conferred on all animals which had a reaction and a 
