388 A MANUAL OF BACTERIOLOGY 



ingestion of tuberculous milk. Even so, the deaths due 

 to the bovine bacillus cannot be more than an eighth or 

 a tenth of the number caused by the human bacillus. 



Spengler and others assert that the bovine bacillus is 

 not virulent to man, and Spengler distinguishes two types 

 of human bacillus (a) the " humanus brevis" the ordinary 

 human type, and (6) the " humanus longus," more 

 virulent and very like the bovine type. 



The occurrence of tuberculosis in the domestic animals raises 

 points of practical importance, especially the occurrence of 

 infection from the consumption of meat and milk from diseased 

 animals. There can be no doubt that the carcase of an animal 

 extensively affected with tuberculosis, especially if wasting has 

 occurred, should be condemned as unfit for food, and likewise 

 all parts in which there are tuberculous deposits. But it becomes 

 an important question for the community, financially as well as 

 from a hygienic point of view, as to the method of procedure with 

 the meat from a beast comparatively slightly affected with tuber- 

 culosis an enlarged gland or two, and a few nodules on the 

 pleura. No doubt the ideal method in such a case is the con- 

 demnation and destruction of the whole carcase, be the amount 

 of tubercle ever so little ; but from financial considerations this 

 procedure is hardly practicable on account of the large amount 

 that would have to be paid in compensation. Experiment has 

 demonstrated that the tubercle bacilli are practically confined to 

 the tuberculous areas and are extremely rarely met with in the 

 muscular tissue, and these portions, therefore, it might seem, 

 could be eaten with impunity, especially as they would be cooked 

 before consumption. (As regards swine, however, tuberculosis 

 anywhere condemns the whole carcase.) But there are two risks. 

 Firstly, in cutting up a carcase the butcher will most likely use 

 the same knife throughout, and in this way may smear the meat 

 with tuberculous matter. Secondly, cooking cannot be depended 

 upon to destroy the bacilli unless the joints are under 6 Ib. in 

 weight ; when the weight is above this the temperature in the 

 interior may not rise sufficiently high. The abolition of private 

 slaughter-houses and the establishment of municipal abattoirs, 

 where the meat would have to be passed by competent inspectors, 



