228 PATHOGENIC BACTERIA IN MILK 



Koch's conclusions are Delepine/ De Jong,^ Arloing,^ Ravenel,"* 

 Fibiger and Jensen,^ Spronck and Hoefnagel,^ Max Wolff/ and 

 Hamilton.* These experiments included a variety of inoculations 

 and some feeding experiments. In all, thirty-nine positive results 

 were obtained, that is, in thirty-nine instances human tubercle 

 inoculated into cattle set up a greater or lesser degree of tuber- 

 culosis. None of these inoculations were of artificial cultures of 

 B. tuberculosis, but of virulent bacilli direct from human sources. 

 Arloing's thirty-three positive results are not included, as they 

 were obtained by inoculation with cultures. There can, we think, 

 be no doubt of the authenticity of these experiments, and the 

 only points of criticism which arise in relation to them are : {a) 

 that the human tuberculosis may have been, in point of fact, of 

 bovine origin, and the bacillus in some or all of the cases of the 

 bovine species ; or {b) that the resulting tuberculosis was in some 

 of the cases of a limited degree, or so strictly localised as not to be 

 of a positive nature. The first criticism may be set on one side. It 

 cannot be proved, nor can it be contested. If it be true, it estab- 

 lishes the proposition that bovine tuberculosis is communicable to 

 man. If it be false, the proposition that human tuberculosis is 

 communicable to animals is proved. The validity of the second 

 criticism must depend upon definitions of what positive result 

 means. If the tubercle bacillus which is inoculated is growing, 

 and reproducing itself, and is setting up tissue changes, and such 

 affected tissues if inoculated in guinea-pigs set up the disease 

 once more, we hold strongly that the result should be considered 

 positive, irrespective of the degree or particular organ affected.® 



^ Brit. Med. Jour., iQoi? ii-> 1224. ^ La Seniaine Medicale, 1902 (15th Jan.). 



3 Bull. Acad, de Med., Dec. 1901, ■a.wA Jour, de Med. Veterinaire, May 1903. 



* Intercommunicability of Human and Bovine Tuberculosis, Philadelphia, 

 1902 ; Univ. of Pennsylvania, Med. Bull., May 1902. 



^ Berliner Klin. Woch., 1902, No. 38. 



® La Semaine Medicale, 15th October 1902. 



^ Deutsche Med. Woch., 1902, No. 32. 



^ Trans, of the Highland and Agricultural Society of Scotland, 1903. 



^ Whilst the present volume was passing through the press the result of 

 further experiments was announced from Berlin. From these it appears that 

 Kossel reports that out of the experiments conducted by the Imperial Depart- 

 ment of Health human bacilli had in two cases only affected the animals under 

 experiment. Orth, on the contrary, reported 10 per cent, of his inoculations on 

 calves as positive, and inducing progressive tuberculosis. Some of these were 

 subcutaneous injections. Behring also reports positive results. An elaborate 

 review of recent knowledge by Kober appears in Amer. Jour. Med. Sc, Oct. 

 I903,pp. 684-705. 



