294 BACTERIOLOGY. 



" (Ji) Cows should not be tested within a few days 

 before or after calving, for experience has shown that 

 the result at these times may be misleading. 



" (i) The tuberculin test is not recommended for 

 calves under three months old. 



" (j) In old, emaciated animals and in re-tests use 

 twice the usual dose of tuberculin, for these animals 

 are less sensitive. 



" (k) Condemned cattle must be removed from the 

 herd and kept away from those that are healthy. 



" (/) In making post-mortems the carcasses should 

 be thoroughly inspected, and all of the organs should 

 be examined." 



Tuberculin injections are also made in man to reveal 

 a suspected tuberculosis. At first some believed that the 

 irritation aroused in the tuberculous foci by the tuber- 

 culin sometimes caused a dissemination of the bacilli and 

 an increase in the disease. When carefully used, how- 

 ever, in suitable cases there is probably no danger. A 

 drawback to its usefulness is that it does not reveal at 

 all the extent of the disease, nor whether the tuber- 

 culosis is active or dormant. It is, however, of great 

 value in selected cases, both surgical and medical, 

 where slight tuberculosis is suspected, and yet no de- 

 cision can be reached. I quote here Dr. Trudeau upon 

 the use of the test. 



"In the absence of any well-defined rules founded 

 upon the experience of others at the time I began to 

 use the test, the method I adopted has been a purely 

 arbitrary one, and I make no claim for its being the 

 best or the most reliable, although, as far as my own 

 personal experience goes, I have as yet seen no objec- 

 tion to it or any reason to modify it. 





