606 
G. A. JOHNSON. 
and is carried along until it reaches a field that presents fa¬ 
vorable conditions for its development, provided it is not de¬ 
stroyed by natural forces before reaching such fields. The 
lymph glands, especially those of the splanchnic cavities, most 
frequently present favorable fields for the primary development, 
though this may differ somewhat with age, species, and the 
physical condition, not only of the animal economy, but with 
the various organs, as injuries of the osseous tissue, especially 
in the young emboli and stenosis of the small blood vessels, etc. 
The air vessels of the lungs, especially in man, may at times 
present favorable conditions, but these are exceptions, rather 
than the rule. 
While it is quite generally agreed by the medical profession 
that there is more or less danger in the use of the food products 
of tuberculous animals, this phase of the question has never re¬ 
ceived the attention that its importance justly demands. There 
has been but little concerted action upon the part of the medi¬ 
cal profession to prevent the spread of the disease through the 
use of the food products of tubercular animals. 
It appears as though a large per cent, of the busy practi¬ 
tioners have, perhaps unintentionally, arrived at the conclusion 
that to control tuberculosis is beyond the power of man, and 
give the subject very little consideration, other than to prescribe 
such lines of treatment as promise the best results, entirely 
ignoring the fact that their patient is, perhaps, being daily re¬ 
infected through the use of contaminated foods. 
It is evident from the almost unlimited lines of treatment 
that have been advocated, that curative treatment has received 
much more attention than has been given to prophylactic treat¬ 
ment. 
Perhaps you are asking, what can be done to lessen the 
spread of the disease ? In reply I would say that if the logical 
deductions of this paper were followed, all that would be neces¬ 
sary would be to stamp out the disease in the bovine species. 
But to assist in the good work, to hasten its accomplishment, 
and to obviate all danger of a possible error in the views pre- 
