On the other hand the individual engaged in sedentary employment, such as book-keeping, teaching, needlework, etc., should dine later in the day, as it leaves a longer interval for digestion, which is much slower when the individual is confined in a close office or work-room, and where little exercise is taken.[5] Care should be taken in planning meals for this class to avoid food which requires much oxygen, such as fresh pork, fried food, sausage, warm bread, pastry, griddle cakes, etc. The mid-day meal of a brain worker or business man should be light; a soup, glass of milk (hot or cold), fruit, bread and butter, vegetable salad, a broiled chop or steak, etc., are suitable for luncheon. Special attention should be given to the diet of school children. (See p. 153.) Students and children who are obliged to study at night should, as a rule, take some light nourishment before retiring; a biscuit, a piece of bread and butter, or a glass of hot milk, is sufficient. Young girls, who are employed in shops, factories, etc., frequently hurry away to their work in the morning without taking a substantial breakfast. It is needless to say that such action is sure to be followed by a physical breakdown. A glass of hot milk or an egg beaten and added to a glass of milk will serve as an occasional substitute for a more substantial meal, but is not enough to sustain active exercise for any length of time. Another point to consider in the planning of meals is economy of fuel. The thoughtful housekeeper will arrange to have food requiring long, slow cooking, such as stews, soup stock, bread, etc., and ironing done by the same fuel. Broiling, toasting, omelets, etc., require a quick fire. It is in the careful consideration of details that economy in both food and fuel may be exercised. FOOTNOTE: [5] The teacher may make this clear by comparing the digestion of the two classes to the action of the air upon coal in a range with the drafts open and closed, the more rapid combustion, effect of oxygen, etc. * * * * * SUGGESTIVE QUESTIONS. In giving instruction in Domestic Science, the teacher must be careful to explain the meaning of any words used which the pupils would not be likely to understand; for instance, oxidation, combustion, solubility, etc., and many of the terms used in the analysis, such as fermentation, casein of milk, albumen, cellulose, etc. In order to keep the attention of pupils fixed on a subject, frequent illustrations and comparisons should be made. Questioning is one of the best methods of riveting attention, and as every teacher has not the faculty of asking questions, a few suggestive ones are given which may prove helpful. Why do we eat food? What is nitrogenous food? What is its chief office? Where is it to be found? In what section of vegetable kingdom is this compound abundant? What is the chief nitrogenous compound in meat and eggs? Of what is it composed?