362 
JOHN M. PARKER. 
sputum, which is mixed with the dust of the floor.’ ‘ The 
whole question of infection,’ he goes on to say, * has in the 
past year narrowed itself down to infection by sputum and 
by milk, and this fact may be regarded as the acquisition of 
the year.’ ” (Manual of Med. Sc., p. 190). 
We can easily understand, therefore, how a consumptive 
person, having charge of a dairy herd, must become a source 
of danger to that herd, and might become a source of greater 
danger to a healthy herd than even the introduction of a 
tuberculous animal. 
An instance was related to me some time ago by one of 
the State Board of Cattle Commissioners, having a direct 
bearing on this subject. In his capacity as State Inspector 
he was called to see a young heifer which was ailing. There 
was no previous history of disease in the herd ; all the ani¬ 
mals so far as could be traced were perfectly healthy ; no 
new animals had been brought in ; the bull used for service 
was a young, healthy animal with no trace of disease, and yet 
unmistakable symptoms of tuberculosis began to develop in 
this young heifer. (These on post-mortem examination proved 
to be tuberculosis). 
Here was something of a puzzle, which was easily ex¬ 
plained when it appeared on conversation that one of the at¬ 
tendants was far gone with acute phthisis. And I believe if 
this matter was carefully investigated, like causes would be 
found more common than is generally supposed. 
The second source of danger, viz., the nasal discharge of 
diseased animals is analgous to the expectorations of human 
consumptives. Cattle do not actually expectorate, but we 
must remember their bodies are not in the upright position 
of a human being ; their heads are held lower, and conse¬ 
quently any discharge from the lungs runs freely from the 
nasal passages; in this way the manger and woodwork be¬ 
come covered with the discharge, which dries, and subse¬ 
quently particles, becoming detached, mix with the dust and 
dirt, and become a source of danger to the neighboring ani¬ 
mals. 
The second group of ways by which the bacilli may gain 
entrance to the animal body, is by direct infection through 
