as a menace to the herd. This is rendered all
the more necessary when the milk is used for the feeding of
children, who are relatively more susceptible to intestinal
infection than the adult. The early stages of the disease in cattle
are, however, so insidious that no reliance can be placed upon the
detection of the malady by physical means. Fortunately, in the
tuberculin test, a method is at hand, which in a simple, but
effective manner, enables the disease to be distinguished in even
the early stages, long before recognition is possible in any other
way.

=Tubercle bacilli in dairy products.= When infected milk is used for
the preparation of butter and cheese, the organisms inevitably are
incorporated in them. In the separation of milk a relatively large
part of the tubercle organisms in the milk appear in the cream. In
the making of cheese even more of the organisms are held in the
curd. In butter and cheese, as in milk, no growth of the organism
can take place; however, the vitality of the organism is retained
for a considerable number of months. It is not believed that these
products are of much importance in the spread of tuberculosis in the
human family, since they are not consumed by children to any extent.
Cream is to be considered as a means of distribution since it is
often used by children.

=Treatment of tuberculous milk.= It is easily possible to treat milk
or factory by-products so as to render them positively safe. The
process of pasteurization or sterilization is applicable to whole
milk, and when effectively done destroys entirely the vitality of
any tubercle bacilli. In making such exposure, care should be taken
to prevent the formation of the "scalded layer," as the resistance
of the organism toward heat is greatly increased under these
conditions. In a closed receptacle, 140 deg. F. for 15 to 20 minutes
has been found thoroughly effective in destroying this organism. A
momentary exposure at 176 deg. F. is likewise sufficient. This is the
method that is almost universally used in Denmark in the manufacture
of the finest butter.

In the treatment of factory by-products, heat should also be
employed. In Denmark, compulsory pasteurization at not less than
176 deg. F. is required. This treatment prevents not only the
dissemination of tuberculosis among hogs and young cattle, but is
equally efficacious in preventing the spread of foot and mouth
disease.

The per cent of tuberculous milch cows varie