1. I have simplified the dilution method by using a stock glycerine emulsion of the virulent cord, from which the desired dilutions can be readily prepared. The proportion of glycerine should not exceed ⅕ part, if it is desired to retain the full virulence of the emulsion.
2. There is some danger of giving rabies to animals in the dilution immunization treatment, a danger which is not present in the Pasteur method.
3. The dried-cord method does not rest solely upon the principle of dilution, but is based also upon attenuation of the virus.
4. The Pasteur method being entirely free from the element of danger which pertains to the glycerine dilution method and resting upon a sounder experimental basis is the one to be preferred.