(1) As top-milk, as described on page 64; or, (2) by mixing equal
parts of plain milk and ordinary cream (containing about 16 per cent
fat); (3) from any of the milk laboratories it may be ordered
directly.

_Is it better to obtain the 10-per-cent milk by using a mixture of
milk and cream, or as top-milk?_

If one can get milk fresh from the cows, the top-milk is to be
preferred on account of freshness. The food can then be made up when
the milk is but a few hours old. In cities, if one uses bottled milk,
the upper third may also be used. But if one buys milk and cream
separately, it is usually more convenient to mix these, as the cream
will not rise upon milk a second time with any uniformity.

_How can one obtain formulas in which the fat is twice the
proteids?_

By using for dilution a 7-per-cent milk (i.e., milk containing 7 per
cent fat) which serves as the primary formula from which all the other
formulas of this series are derived.

In 7-per-cent milk the fat is just twice the proteids.

_How can one get the 7-per-cent milk?_

(1) As top-milk, as described on page 64; or, (2) by mixing three
parts of milk and one part of ordinary (16 per cent) cream; (3) from
any of the milk laboratories it may be obtained directly. As in the
case of 10-per-cent milk, the top-milk is generally to be preferred to