to
sit for at least four hours, contains 10% of fat, and this is
therefore called 10% milk. The calculation is made as follows:--10%
milk is to the fat percentage desired, as the amount which we wish
to make up is to X. For example, if we wish to prepare twenty
ounces of milk for an infant two months old, we will note by
referring to the table that 3% is the amount of fat that is
desirable for a milk for a child of this age, and the formula will
be constructed as follows:--

10:3::20:X. X = 60/10. X = 6.

Six ounces is then the amount of 10% milk that must be used for
making twenty ounces of modified milk,--this being mixed with one
ounce of lime-water and thirteen ounces of boiled water. It should
never be forgotten that while milk modified by the foregoing
formula is suitable for most children, it is by no means always
satisfactory, and we may, therefore, be compelled to do a
considerable amount of experimenting in some cases before arriving
at the correct formula.

Suppose the infant is twelve months old, we would get according to
the rules just stated the following equation:--

10:4::20:X. X = 80/10. X = 8.

Eight ounces would then be the amount of milk required for
preparing twenty ounces of modified milk for an infant of this age.

In preparing modified milk according to the formulas just given, it
must be remembered that in all instances only that portion is to be
used which collects in the upper third of a bottle of milk that has
been allowed to sit undisturbed in a refrigerator for at least four
hours. The lime-water is for the purpose of correcting the acidity
of the milk.

It is of much importance to select the milk from a healthy cow in
all instances where it is to be fed to infants, and where possible,
it should be examined by a competent laboratory man in order to
determine if it answers the proper requirements. The writer has
often seen milk from apparently healthy cows, which seemed in every
way good, that showed on microscopic examination pus cells and a
harmful germ (streptococcus).

It is not desirable to have a milk for this purpose that is too
rich in fats, and for this reason a cow of the ordinary mixed breed
is more satisfactory than the blooded Jerseys or Alderneys.

Not only is it