, however, that it could live in
raw milk from one to four days, depending upon the amount of acid
present. In boiled or sterilized milk it grows more freely, as the
acid-producing forms are thereby eliminated. In butter it dies out in a
few days (4 to 5).

On account of the above relation not a large number of cholera outbreaks
have been traced to milk, but Simpson[116] records a very striking case
in India where a number of sailors, upon reaching port, secured a
quantity of milk. Of the crew which consumed this, every one was taken
ill, and four out of ten died, while those who did not partake escaped
without any disease. It was later shown that the milk was adulterated
with water taken from an open pool in a cholera infected district.

~Diphtheria.~ Milk occasionally, though not often, serves as a medium for
the dissemination of diphtheria. Swithinbank and Newman[117] cites four
cases in which the causal organism has been isolated from milk. It has
been observed that growth occurs more rapidly in raw than in sterilized
milk.[118]

Infection in this disease is more frequently attributable to direct
infection from patient on account of the long persistence of this germ
in the throat, or indirectly through the medium of an attendant.

~Scarlet fever.~ Although it is more difficult to study the relation of
this disease to contaminated milk supplies, because the causal germ of
scarlet fever is not yet known, yet the origin of a considerable number
of epidemics has been traced to polluted milk supplies. Milk doubtless
is infected most frequently from persons in the earlier stages of the
disease when the infectivity of the disease is greater.

~Diarrhoeal diseases.~ Milk not infrequently acquires the property of
producing diseases of the digestive tract by reason of the development
of various bacteria that form more or less poisonous by-products. These
troubles occur most frequently during the summer months, especially with
infants and children, as in cholera infantum and summer complaint. The
higher mortality of bottle-fed infants[119] in comparison with those
that are nursed directly is explicable on the theory that cows' milk is
the carrier of the infection, because in many cases it is not consumed
until there has been ample time for the development of organisms in it.
Where milk is pasteurized or boiled it is found that the mortality among
children is greatly reduced. As a cause of sickness and death these
diseases