There is abundant evidence that milk is rendered less digestible by
such heating; also that it is more constipating, and that for some
children its nutritive properties are interfered with, so that it may
cause scurvy; this, however, is not seen unless it is continued as the
sole food for a long period. These objections are of so much
importance that this plan of heating milk is not to be recommended for
general use.

_When is it advantageous to heat milk to 212° F.?_

For use upon long journeys, such as crossing the ocean. Milk should
then be heated for one hour upon two successive days, without removing
the cotton stoppers from the bottles.

_Is milk in any way injured by heating to 155° F. for thirty minutes?_

This point is not yet definitely settled. Such heating does not affect
the taste of milk and does not render it more constipating. The
unfavourable effects; if there are any, are so slight that they need
not deter one from the use of pasteurized milk, even for long periods.
The preference, however, should always be given to milk which is so
clean and so fresh as not to require any heating.

_How should milk be pasteurized?_

A convenient form of apparatus is that known as Freeman's
pasteurizer[5]; another is the Walker-Gordon pasteurizer.[6]

[5] This can be obtained at 411 West Fifty-ninth Street, New
York, with bottles and full directions; a tin one, at a cost of