414 DISEASES OF CATTLE. 



these cases earlier tests had been made months or years before. In 28 cases the 

 injecticn took place from nineteen days to two months before the butchering; in 

 3 of these cases earlier injections had been made. In 38 cases from two and 

 one-half months to one year intervened between the last injection and the dissec- 

 tion. Dissection gives the best explanation of this question, but a clinical obser- 

 vation, continued for years, of a herd tested with tuberculin can render very 

 essential aid. If Hess'a opinion is correct, it is to be assumed that tuberculosis 

 must take an unusually vicious course in such herds, but this I have been unable 

 to prove. At Thurebylille there has existed for three years a reacting division, 

 consisting originally of 131 head and now of 69, Although these animals are 

 yearly tested, and although most of them react every year, the division certainly 

 appears to be made up of healthy animals, and the farm inspector has expressed 

 the decided opinion that the tuberculosis in this division is no more developed 

 than at the beginning of the experiment. The testimony of many owners of large 

 herds of cattle which have long ago been injected is to the same effect, I will 

 adduce statements from several. A farm tenant whose cattle were injected twenty 

 months previously, when 82 per cent of the grown animals reacted, wrote me 

 recently as follows: " Only 2 cows from the division of 100 head had been sold as 

 decidedly tuberctdous. The majority appeared afterwards, just as before, entirely 

 healthy. The fat animals which had been slaughtered had been pronounced 

 healthy by the butchers. ' ' Another farm tenant with a herd injected in 1894 had 

 not been obliged to remove a single animal from the tuberculosis division, num- 

 bering 70 head. A large farm owner in Jutland stated in September that he had 

 traced no undesirable result from the injection. His herd of 350 had been injected 

 in February and about 75 per cent reacted. Similar answers have been given by 

 other owners and veterinarians. 



A veterinarian who had injected 600 animals, among them a herd of a large 

 farm, eighteen months previously, expressed the belief that the injection had pro- 

 duced in no single case an unusually rapid or vicious course of tuberculosis. In 

 spite of a demand made months ago, I have received thus far no report from any 

 veterinarian of an undesirable result. 



On a large farm, on which before the injection tuberculosis had appeared in a 

 vicious form, the owner had the impression that the severe cases had afterwards 

 become more numerous. He had, however, not suffered severe losses, and eight 

 months later the large reacting division by no means made a bad impression. 

 Finally, it is to be noticed that tuberculin has been employed on a large scale in 

 Denmark for years, and still the demand from farmers constantly increases. This 

 could certainly not be the case if the injections were generally followed by bad 

 results. 



Paige said, after the tests of the herd of the Massachusetts Agri- 

 cultural College, that "its use is not followed by any ill effects of a 

 serious or permanent nature." 



Lamson, of the New Hampshire College Agricultural Experiment 

 Station, said: "There is abundant testimony that its use is not in any 

 way injurious to a healthy animal." 



Conn, who made a special study of the present attitude of Euro- 

 pean science toward tuberculosis in cattle, reached the following 

 conclusions : 



It has been, from the first, thought by some that the use of tuberculin produces 

 a direct injury upon the inoculated animals. This, however, is undoubtedly a 

 mistake, and there is no longer any belief anywhere on the part of scientists that 

 the injury thus produced is worthy of note. In the first place, the idea that it 

 may produce the disease in a perfectly healthy animal by the inoculation is abso- 



