DR. J. M. BEATTIE'S PAPER 171 



are usually absent. Even to the expert bacteriologist, 

 the difficulty of distinguishing them from B. tuber- 

 culosis by microscopical methods is very great, and 

 in two samples which came under my observation 

 quite recently it was quite impossible to do so. 



(3) It has been clearly established by several 

 observers that B. tuberculosis may be present and 

 may produce tuberculosis, though it does not react 

 to the regulation staining process. The microscope 

 is useless for the discovery of these organisms. 



These three difficulties, not to mention others, 

 which present themselves to the expert bacteriologist 

 prove how unsatisfactory it would be to allow this 

 microscopical examination to be the sole test for 

 tuberculous milk, and how disastrous it would be to 

 place the examination in the hands of inexperienced 

 individuals. The inoculation method if carried out 

 properly guarantees that every sample of tuberculous 

 milk will be discovered, and for the microscopical 

 methods even its strongest advocates do not claim 

 more than 90 per cent, of successes. In inexperienced 

 hands the failures will undoubtedly amount to 40 or 

 50 per cent., and yet, in spite of these facts, we find 

 that by the Tuberculosis Order, 1913, the Board of 

 Agriculture has given power to the local authorities 

 to accept microscopical examination by veterinary 

 inspectors in suspected animals as sufficient examina- 

 tion to decree the slaughter. 



I do not question the ability of some of these 

 inspectors, but to give this general power is to my 

 mind one of the most retrograde steps which has 

 ever been taken in the tuberculosis campaign, and it 

 will undoubtedly lead not merely to the slaughter of 

 non -tuberculous animals a fact that will tend to 

 bring the whole process of inspection into disrepute 

 but, what is more serious, to the selling of undetected 

 tuberculous milk with the false security that proper 

 inspection and examination is being carried out. 



