1895.] MICROSCOPICAL JOURNAL. 221 



no definite opinion, but we think it probable that an appreci- 

 able part of the tuberculosis that affects man is obtained through 

 his food. The circumstances and conditions with regard to the 

 tuberculosis in the food animals which lead to the production of 

 tuberculosis in man are, ultimately, the presence of active tu- 

 berculous matter in the food taken from the animal and con- 

 sumed by the man in a raw or insufficiently cooked state. Tu- 

 berculous disease is observed most frequently in swine and in 

 cattle. It is found far more frequently in cattle (full grown) 

 than in calves and with much greater frequency in cows kept 

 in town cow-houses than in cattle bred for the express purpose 

 of slaughter. Tuberculous matter is but seldom found in the 

 meat substance of the carcase ; it is principally found in the or- 

 gans, membranes, and glands. There is reason to believe that 

 tuberculous matter, when present in meat sold to the public, is 

 more commonly due to the contamination of the surface of the 

 meat with material derived from other diseased parts than to 

 disease of the meat itself. The same matter is found in the 

 milk of cows when the udder has become invaded by tubercu- 

 lous disease, and seldom or never when the udder is not dis- 

 eased. Tuberculous matter in milk is exceptionally active in 

 its operation upon animals fed either with the milk or with 

 dairy produce derived from it. No doubt the largest part of 

 the tuberculosis which man obtains through his food is by 

 means of milk containing tuberculous matter. The recognition 

 of tuberculous disease during the life of an animal is not wholly 

 unattended with difficulty. Happily, however, it can in most 

 cases be detected with certainty in the udders of milch cows. 

 Provided every part that is the seat of tuberculous matter be 

 avoided and destroyed, and provided care be taken to save from 

 contamination by such matter the actual meat substance of a 

 tuberculous animal, a great deal of meat from animals affected 

 b}^ tuberculosis may be eaten without risk to the consumer. 

 Ordinary processes of cooking applied to meat which has got 

 contaminated on its surface are probably sufficient to destroy 

 the harmful quality. They would not avail to render whole- 

 some any piece of meat that contaminated tuberculous matter 

 in its deej)er parts. In regard to milk, we are aware of the 

 preference by English people for drinking cows milk raw — a 



