No. 6. DEPARTMENT OF AGRICULTURE. 13» 



the mixed milk of live cows was examined by iutraperito-ueal inocu- 

 lation ot guinea-pigs. These cows had reacted to tuberculin, but 

 were in good conditiou aud ot hue appearance. Repeated examina- 

 tions ot the udders by several vetermarians failed to reveal any 

 lesion, and examination after the death of the a-nimals gave the same 

 negative results. Ko attempt was made to concentrate the bacilli; 

 on the contrary, the whole quantity of milk was well shaken, in order 

 to imitate as nearly as possible natural conditions, and moderate 

 doses of milk (lU c. c.j were used. Of eighty-eight guinea-pigs em- 

 ployed in this test sixty-three lived long enough for the development 

 of tuberculosis, and of these ten, or lo.S per cent., became tubercular. 

 More surprising and more unusual are the results of Uabinowitsch 

 and Kempuer, who inoculated the milk of tifteeu cows into guinea- 

 pigs, the experiment beiug made to determine whether or not the 

 milk of cows having a tuberculosis which could be detected only by 

 tuberculin, and not by physical examination, might be virulent. 

 Three examinations were made by a veterinarian in the course of the 

 experiment. Of the fifteen animals ten were found to give virulent 

 milk, a percentage of GG.G. One cow gave milk which contained a 

 yellowish, gelatinous material, and caused a fatal peritonitis in a 1 

 animals inoculated. Leaving this out, the positive results amount to 

 71.4 per cent. All of the cows had reacted to tuberculin, but none 

 showed clinical evidence of udder disease when the experiment be- 

 gan. Of the ten giving virulent milk three showed advanced gen- 

 eral tuberculosis, but no disease of the udder; two showed no evi- 

 dence of disease at al', and one only on the second and third examina- 

 tions. One cow had rales at the time of first examination, but these 

 disappeared, and she showed no evidence of disease after. On post- 

 mortem one cow was found to have tuberculosis of the udder, aud one 

 showed clinical evidence of it on the third examination, made six 

 months after the experiment was begun. The authors conclude: 

 ''Milk may contain tubercle bacilli, first, in beginning tuberculosis, 

 witliout discoverable disease of the udder, and, second, in latent 

 tuberculosis that can be detected only by the tuberculin reaction;" 

 also, "milk from cows that react to tuberculin must be suspected of 

 being infectious in every case," 



\Mth thes results before us we must admit that while tuberculosis 

 of the udder is the most dangerous condition, we cannot by any 

 means regard the milk of cows with general tuberculosis, but the 

 udders of which are free from the disease, as being safe for food. 

 \^'e must insist that danger is not limited to those herds which 

 ' rirbor one or more cows with udder tuberculosis. I cannot agree 

 with those writers who attempt to belittle the dangers to which 

 milk-fed babies are exposed by pointing out the comparative infre- 



