Disease Bacteria in Milk. 81 



pigs and rabbits was innocuous when diluted with healthy 

 milk to 50-100 times its volume. Therefore, there is less 

 danger in mixed herd milks, than in that of a single cow, 

 unless it is positively known that she is unaffected with 

 the disease. 



2. Destruction by heat. If milk containing tubercle 

 bacilli is boiled, the disease organism is destroyed. The 

 same result may be accomplished by pasteurizing if this 

 process is correctly carried out. A temperature of 155- 

 160 F. for fifteen to twenty minutes is sufficient for this 

 purpose. 



3. It has been suggested that inasmuch as centrifuging 

 seems to throw out many of the tubercle bacilli in the 

 slime 1 that this method of purification could be used, but 

 Moore 2 has shown that no reliance can be placed on this 

 method. 



79. Foot and mouth disease. This disease is dis- 

 tinctively an animal malady, but it is also transmissable 

 to man, although it is not often fatal. Hertwig 3 records 

 some experiments made on himself. After drinking milk 

 from an animal suffering from this disease, the mucous 

 membrane of the mouth became swollen, small vesicles 

 appearing in the mouth. Not an inconsiderable number 

 of epidemics have been reported that have been traced to 

 this source. 4 Calves readily acquire the disease suckling 

 affected mothers. The law in Prussia since 1894 requires 

 that the milk from all infected herds shall be heated to 

 194 F., for fifteen minutes before it is taken from the 

 dairy. 



1 Bang, Milch Zeitung, 1893, p. 672. 

 8 Moore, Year Book, Dept. of Agriculture, p. 432, 1895. 

 3 Ziemssen, Cyclop, of Prac. of Med., 3: 521. 

 4 Freeman, Med. Record, March 28, 1896. 

 6 B. 



