and Laboratory Methods. 1549 



beijigs and very rarely fro7n cattle. This belief he bases upon his first conclusion, 

 and also upon the fact that in mankind primary tuberculosis in the intestinal 

 tract is quite rare, while, if the disease were commonly due to the consumption 

 of flesh or milk, primary intestinal tuberculosis should be frequent. 



It was inevitable that these bold conclusions should be received by the 

 members of the congress with consternation and disapproval. Many of the 

 members of the congress had appeared especially prepared to discuss the 

 dangers to mankind of the distribution of tuberculosis by milk or flesh of cattle, 

 and the sweeping conclusions of Prof. Koch inevitably destroyed, in a large 

 degree, the significance of many of the papers read before the congress. The 

 members of the congress did not accept the conclusions of Prof. Koch, and 

 nearly all of the remarks which referred to the paper took a position quite 

 opposite to that occupied by the discoverer of the tubercle bacillus. The 

 opinion was expressed that Prof. Koch had done the cause of public health a 

 great injury by advancing unproved conclusions which would tend to decrease 

 the care given to the methods of preventing the use of tuberculous material as 

 food, and thus making the work of sanitary boards more difficult. Indeed, a 

 resolution was passed in the State and Municipal Section to the effect that the 

 conclusions of Prof. Koch were not demonstrated, and that the same amount of 

 care should be exercised in preventing the use of tuberculous material as before 

 the publication of the address of Prof. Koch. 



Since the closing of the congress bacteriologists of repute have expressed in 

 public opinions as to the conclusions taken by Prof. Koch. These are too 

 numerous to be mentioned in this place, but the attitude taken by some of the 

 more prominent bacteriologists may be properly mentioned. 



It must be noticed at the outset that the first conclusion is not new with 

 Prof. Koch, for Theobold Smith of Harvard University had already some years 

 ago demonstrated conclusively that the human bacillus is only slightly, if at all, 

 pathogenic for cattle. This conclusion was, therefore, well known, and the only 

 novelty in Prof. Koch's address is in the claim that bovine tuberculosis is not a 

 source of human tuberculosis. In regard to Prof. Koch's claims, wide 

 divergence of opinion may be found among bacteriologists who have commented 

 on the matter. Prof. Virchow ( Ber. K/m. Woc/i., p. 8i8, JQOi) expresses himself 

 as of the opinion that there is a difference between the bovine and human 

 bacillus, though not so great a one as Prof. Koch is inclined to think. He 

 believes that many of the tubercles which have been described as due to tuber- 

 culosis are not properly described, and that histological study of the tubercles 

 alone can be depended upon to determine the presence of this disease, and not 

 the simple presence of a tubercle which stains properly. He insists that the 

 second conclusion of Prof. Koch is not justified, and that there are cases on 

 record which show that the disease may pass from cattle to men, although the 

 danger is slight. He thinks that more attention must be paid to the tiumber of 

 bacteria inoculated than has been paid hitherto. Prof. Klebs {Milchztg., p. 501, 

 1901 ) very violently attacks Koch's position, claiming that both of Koch's con- 

 clusions are erroneous ; that the bacillus is the same in cattle and men, and the 

 milk and flesh of tuberculosis animals are a prominent source of danger to man. 



