nown to persist for a period of three weeks before elimination.

On account of the elimination of many drugs, unchanged, from the
animal in the milk, the milk of any animal that is receiving
medicine should not be used for human food. When such milk is mixed
with that of a number of other animals and when it is used by
adults, no harm is likely to result, but when the dilution is not
great and the milk is used for young children it may affect them
through its content of the drug. The feed may not only affect the
quality of milk but its value as food. One of the most prominent of
American dairymen, who has for many years produced milk especially
for children's use, has said that he could feed his cows so as to
make ill every child receiving the milk.

=Absorption of odors after milking.= If milk is brought in contact
with strong odors after being drawn from the animal, it will absorb
them readily, as in the barn, where frequently it is exposed to the
odor of manure and other fermenting organic matter.

It has long been a popular belief that milk evolves odors and cannot
absorb them so long as it is warmer than the surrounding air, but
from experiments of one of us (R), it has been definitely shown that
the direct absorption of odors takes place much more rapidly when
the milk is warm than when cold, although under either condition, it
absorbs volatile substances quite rapidly.

The custom of straining the milk in the barn has long been
deprecated as inconsistent with proper dairy practice, and in the
light of the above experiments, an additional reason is evident why
this should not be done.

Even after milk is thoroughly cooled, it may absorb odors, as is
noted where the same is stored in a refrigerator with certain
fruits, meats, fish, etc.

=Distinguishing bacterial from other taints.= In perfectly fresh milk
it is relatively easy to distinguish between taints caused by the
growth of bacteria and those attributable to direct absorption. If
the taint is evident at time of milking, it is in all probability
due to character of feed consumed, or possibly to medicines. If,
however, the intensity of the taint grows more pronounced as the
milk becomes older, then it is probably due to living organisms
which require a certain period of incubation before their
by-products are most evident.

Moreover, if the difficulty is of bacterial origin, it can be
frequently produced in another lot of milk (heated or sterilized is