The present communication is the outcome of observations made during the past two years, at the request of vaccine propagators, regarding the best methods of preserving vaccine lymph. It is our purpose to refer briefly to the contaminations by bacteria occurring in bovine vaccine lymph with their effects and to the measures which have been found useful in preserving the virus. No reference will be made to humanized lymph, as the danger of syphilitic infection through its use has practically stopped its employment.
The bacterial contaminations may be divided into two classes: The saprophytes or non-pathogenic, and the parasites or disease-producing. The former are of moment, because by their presence and growth the virus is decomposed and by some at least is robbed of its specific property. The pathogenic variety may cause various disease processes in the human subject when virus containing them is employed for vaccination.
Abundant observations have