83 
THE TUBERCLE BACILLUS. 
A VALUABLE and instructive article was contributed to Part II. 
of the Journal, last year by Mr. Duguid, on " Tuberculosis 
in Animals, and its relation to Consumption in Man," in which 
the author pointed out that this subject was of just as much 
interest and importance to stock-owners and others connected 
with the cattle trade as to Sanitary Medical officers and 
guardians of the public health. 
Mr. Duguid fully justified this statement in a very temperate 
discussion of the possible transmission of tuberculosis from the 
cow to man by the flesh and milk of animals suffering from this 
disease, and especially in his concluding remarks on the need 
for legislation in Great Britain in connection with this subject, 
and on the vexed questions of slaughter and compensation. 
No scientific subject of late has received so much attention 
in the columns of the daily and agricultural press as tuberculosis, 
and indeed the tubercle bacillus has been a topic of daily 
conversation. There is a desire for information on the part of 
intelligent laymen, while in scientific professional circles the 
interest attaching to tuberculosis is steadily increasing, and the 
importance of a thorough investigation of the subject in all its 
aspects is daily becoming more fully recognised. It is proposed, 
in this paper, to give some account of the tubercle bacillus and 
its pi'oducts, and of the effect of Koch's liquid on tubercular 
animals, avoiding as much as possible all technical expressions, 
which would I'ender the account unintelligible to many. 
The Discovery of the Tubercle Bacillus. 
It had long been known that consumption or tuberculosis 
was communicable from one animal to another by experimental 
inoculation, but investigators failed to find out the cause or 
contagium. In 1882, Koch discovered the Bacillus tuberculosis, 
and published the evidence upon which he based his conclusion 
that this microbe was the germ of the disease. 
This minute parasite is a vegetable organism. It is found 
in all forms of tuberculosis in man and the lower animals. It 
is readily detected in the sputum or expectoration of human 
patients suffering from phthisis or tuberculosis of the lungs. 
The discovery of this micro-organism was therefore of the 
greatest possible value, for its presence is a certain indication 
of the existence of tubercular disease (see Plate I.). 
G 2 
