MILK INSPECTION. 
983 
sometimes acquired by milk is attributable to strong food of 
some kind, but it is now known that it may be of bacterial 
origin. Abnormal colors, and disagreeable odors are sometimes 
traceable to the same cause. Aside from the bacteria that are 
harmless and those that produce fermentation, there are patho¬ 
genic (disease-producing) germs sometimes found in it. Tuber¬ 
culosis may be instanced as to the most common disease affect¬ 
ing bovines and man alike ; it is the disease most to be feared. 
Slow and insidious in its nature, it affects the appearance of an 
animal usually after long infection. For years the animal may 
be apparently healthy, all the organs seeming to perform their 
natural function, but long before the time when the cow shows 
signs of disease and the milk becomes thin and otherwise un¬ 
natural in appearance, she may be disseminating the germ of 
tuberculosis. Notwithstanding the view of Dr. Koch that the 
danger of transmission of tuberculosis to man through the flesh, 
milk and milk products of tuberculous cattle, is hardly greater 
than that of hereditary transmission, there is ample justification 
for not removing any sanitary barriers at present. Even the 
Congress before which his opinion was delivered, did not sus¬ 
tain his opinion, but overwhelmingly decided against him. 
The bacteria that produce diphtheria, typhoid fever, scarlet 
fever, through the agency of milk, do not gain entrance to it 
from sick cows, as has sometimes been supposed, but partly by 
the milk being held in open vessels in rooms adjacent to those 
occupied or frequented by persons suffering or convalescing from 
those diseases. 
Bacteria are vegetable, microscopical bodies that produce 
the changes in animal and vegetable substances, known as de¬ 
composition, putrefaction, decay, etc. They are so small that 
millions of them have been found in a drop of badly tainted 
milk. They vary in size and shape and multiply rapidly by 
division of the cells and the production of spores. During 
growth some of them develop poisonous chemical ptomaines. 
Most species develop rapidly where heat, moisture and animal, 
also vegetable matter are abundant. Some require air to grow 
