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 three weeks' food for the chicken, therefore must have fuel food as well. This fuel food is found in the yolk, in the form of fat.
5. The yolk therefore contains water, mineral matter, protein, and fat.
6. The white contains water, mineral matter, and protein.
EFFECT OF HEAT ON EGGS
The following experiments will show the effect on both yolk and white of the usual methods of applying heat to eggs:
1. Boil an egg for three minutes and note the effect.
2. Boil an egg for twenty minutes and note the effect.
3. Put an egg in boiling water, remove from the fire, and let it stand covered from eight to ten minutes.
4. Fry an egg and note the effect.
NOTE.--The eggs may be put to boil and simmer at the beginning of the lesson, and pupils designated to take them from the heat at proper times. The eggs will then be ready to examine when required.
CONCLUSIONS
1. Boiling an egg for three minutes does not allow time for the heat to reach the yolk. The white is hard and tough just next the shell, but soft and liquid as it approaches the yolk.
2. Boiling an egg for twenty minutes hardens and toughens the white, so that it all becomes hard to dissolve or digest. It also gives the heat time to reach the centre and hardens the yolk, but does not toughen it or make it hard to dissolve or digest.
3. Allowing the egg to stand in the hot water coagulates the white to a jelly-like consistency without toughening it; it also cooks the yolk.
LESSONS III, IV, ETC.
USES OF EGGS
To give practice in preparing eggs and to show their special uses the following dishes would be suitable:
1. White:
For food--poached eggs on toast, simmered eggs
For cohesive (sticky) property--potato balls, fish balls
For clearing liquids--coffee
For holding air--foamy omelet
For decoration--hard-boiled eggs cut in fancy shapes for garnishing, meringue on lemon pudding, etc.
2. Yolk:
For food--egg-nog, scrambled eggs
For thickening liquids--custard, salad dressing, lemon pudding
For colouring foods--tapioca cream
For decoration--hard boiled and grated over salads.
STUDY OF VEGETABLE FOOD
Before beginning this part of the work, it would be most helpful if the class had one or two nature study lessons on the structure and organs of plants. With the pupils in possession of some knowledge thus acquired, the Household Management teacher has only to lead up to ideas of the preparation and value of these parts as food. These ideas should, as far as possible, follow in such a natural order that the pupils may even anticipate the sequence.
The outline may be as follows:
LESSON I
SOURCE
All vegetable food is obtained from plants; it is some part of a plant used as food.
PARTS OF PLANTS USED AS FOOD
1. Root--carrot, radish
2. Tuber--potato, artichoke
3. Bulb--onion
4. Stem--rhubarb, asparagus
5. Leaf--spinach, cabbage
6. Flower--cauliflower
7. Fruit--apple, orange
8. Seed--(1) Of trees (nuts)--beechnut, almond