ed milk.

STUDY OF EGGS

LESSON I

PARTS

(1) Shell, (2) thick membrane, (3) white, (4) thin membrane, (5) yolk.

These parts are easily seen. Attention should be called to the pores in
the shell, and it should be explained that these allow the entrance of
bacteria which spoil the egg. Any means of closing these pores helps to
preserve the egg.

METHODS OF PRESERVING

Cover the holes in the shell as follows:

1. Pack in salt, bran, sawdust, brine, or water-glass.

2. Coat the shells with fat or wax.

3. Wrap the eggs in paper.

[Illustration: Testing eggs by floating: (1) slightly stale, (2) stale,
(3) very stale]

TESTS

1. In the shell:

After an egg is laid, the liquid which it
contains begins to evaporate through the pores
of the shell and, as this continues, a
noticeable space is left inside.

(1) Shake the egg, holding it near the ear. If
the contents rattle, it is somewhat stale.

(2) Drop the egg in cold water. If it sinks, it
is fresh.

(3) Hold the egg between your eye and the
light. If clear, it is fresh.

(4) A rough appearance of the shell denotes
freshness.

2. Out of the shell:

White--this should be clear and cling to the
yolk.

Yolk--this should round up like a ball.

CARE

1. If eggs are to be used in the near future, they should be washed and
put in a pure, cool atmosphere. The lower shelf of the refrigerator is
best, as odours rise, and eggs readily absorb these.

2. If eggs are to be preserved, they should not be washed unless their
condition compels it, as washing removes the natural covering of the
pores. They should be stored in a clean, cool place, and packed as soon
as possible.

LESSON II

COMPOSITION

It is wiser to develop the food substances in an egg by reasoning,
rather than by examining the different parts. The shell is not used for
food, so it is the contents that should be studied. The class should be
guided in the following sequence of thought:

1. An egg is designed by nature to become a chicken, so it must contain
all of the substances necessary to build a chicken.

2. A chicken is an animal, and all animal bodies are made of the same
substances. These we have seen to be mineral matter, protein, and water.

3. An egg therefore contains these three substances.

4. An egg must also contain t