480 
“ restraining ” action of the milk, inhibition resulting from strange 
media, etc. Others believe that fresh raw milk possesses definite, 
though feeble, germicidal properties. Some of the authorities cited 
absolutely deny not only the germicidal but also the restraining 
power of milk, claiming a steady increase in numbers from the start. 
Fokker® was the first to call attention to the bactericidal prop- 
erties of milk. He was led to investigate this subject through the 
results of Xuttall, Buchner, and Lubarsch, who found that blood 
contained substances capable of destroying bacteria. Fokker 
obtained goats’ milk under careful aseptic precautions and divided 
it into two portions, one of which was heated, and both portions 
then infected with bacteria of souring milk. The cooked portion 
would always sour within twenty- four hours, while the fresh, un- 
heated portion would keep at least, and sometimes more than, three \ 
or four daj^s. 
He also noted that by the use of cultures on plates there was first 
a diminution in the number of bacteria in milk. He further found | 
that the brief heating of milk did not always destroy its bactericidal i 
properties, but that prolonged heating at 70° C. is sufficient to destroy 
this action. 
Uffelmann * observed the multiplication of cholera vibrios during 
the first twelve to sixteen hours in raw milk to be less than in the 
controls with cooked milk. 
Weigmann and Zirn also investigated the question of cholera 
vibrios in raw milk and found a diminution in the first four hours, 
but not in cooked milk. They believe that the presence of acid 
causes the killing of the vibrios. 
A few years later, 1894, Hesse ^ confirmed the pioneer work of 
Fokker and stated most positively that cholera and typhoid are 
both killed by fresh milk and concludes from his studies as follows : 
The killing of the organisms begins the moment the cholera bacilli are added 
to the milk. This is complete, almost without exception, at room temperature ^ 
(15°-20° C.) within twelve hours; at incubator temperature within six to eight 
hours. The destruction of the organisms is independent of the acid content of 
the milk, and independent of the milk organisms and their metabolic products. 
It is more probably to be looked upon as a vital function of the living milk, 
which is immediately lost upon heating to 100° C. 
He, therefore, recommended the use of raw milk as a therapeutic 
measure in cholera. 
® Fokker, A. P. : Ueber die bacterienvernichtenden Eigenschaften der Milch. 
Fortschr. der Med., vol. 8, 1890, p. 7. 
® Uffelmann, J. : Beitrage zur Biologie des Cholerabacillus. Berl. klin. Woch., 
vol. 29, 1892, p. 1209. 
^ Weigmann, H., and Zirn, Gg. : Ueber das Yerhalten der Cholerabakterien in 
Milch und Molkereiprodukten. 
^ Hesse, Walter : Ueber die Beziehungen zwischen Kuhmilch und Cholerabacil- 
len. Zeit. f. Hyg., vol. 17, 1894, p. 238. 
