should, of course, be dispensed in sterilized bottles. Glass bottles
with plain pulp caps are best, and these should be thoroughly sterilized
in steam before using. The bottling can best be done in a commercial
bottling machine. Care must be taken to thoroughly clean this apparatus
after use each day. Rubber valves in these machines suffer deterioration
rapidly.

[Illustration: FIG. 29. Relative consistency of pasteurized cream before
(A) and after (B) treatment with viscogen as shown by rate of flow down
inclined glass plate.]

~Restoration of "body" of pasteurized cream.~ The action of heat causes
the tiny groupings of fat globules in normal milk (Fig. 22) to break up,
and with this change, which occurs in the neighborhood of 140 deg. F.,
where the milk is heated for about 15 minutes and at about 160-165 deg.
F. where rapidly heated in a continuous stream, the consistency of the
liquid is diminished, notwithstanding the fact that the fat-content
remains unchanged. Babcock and the writer[152] devised the following
"cure" for this apparent defect. If a strong solution of cane sugar is
added to freshly slacked lime and the mixture allowed to stand, a clear
fluid can be decanted off. The addition of this alkaline liquid, which
is called "viscogen," to pasteurized cream in proportions of about one
part of sugar-lime solution to 100 to 150 of cream, restores the
consistency of the cream, as it causes the fat globules to cluster
together in small groups.

The relative viscosity of creams can easily be determined by the
following method (Fig. 29):

Take a perfectly clean piece of glass (plate or picture glass is
preferable, as it is less liable to be wavy). Drop on one edge two or
three drops of cream at intervals of an inch or so. Then incline piece
of glass at such an angle as to cause the cream to flow down surface of
glass. The cream, having the heavier body or viscosity, will move more
slowly. If several samples of each cream are taken, then the aggregate
lengths of the different cream paths may be taken, thereby eliminating
slight differences due to condition of glass.

FOOTNOTES:

[126] From 10 to 16 cents per quart is usually paid for such milks.

[127] Much improvement in quality could be made by more careful control
of milk during shipment, especially as to refrigeration; also as to the
care taken on the farms. The use of the ordinary milking machine (see
page 37), would go far to reduce the germ content o