d. =The Dietetic Control of Sleep.=--Most students study evenings. If their heavy meal is a dinner at 5:30 or 6 p.m. they are likely to feel very drowsy by 7:30 or 8 o'clock. This is a perfectly natural experience, all animals manifesting a drowsiness after a heavy meal. If one could lie down and sleep for an hour while his dinner is digesting, he could probably rise at 9 o'clock and put in two or three hours of good hard work. He would find himself at 11 or 12 o'clock so thoroughly awake, however, that he might have difficulty in getting to sleep if he retired at that hour. If, on the other hand, one has his dinner in the middle of the day and a light supper at night, he is able to begin studying within an hour after supper and keep it up until he is ready to retire. In this case also, he is likely to be so wide awake at the time of retiring that he may have difficulty in getting to sleep. In either of these cases, it is altogether proper and advisable to take a light lunch before retiring. A double purpose can be served by this lunch. In the first place, the taking of anything into the stomach that requires digestion tends to deplete the circulation from other organs (brain in this case) to the stomach. In the second place, the food may be so chosen as to exert a definite _somnolent_ effect. Such foods are, _celery_, _lettuce_, _onions_, _warm milk_. It may not be convenient to get warm milk at midnight, but it would hardly be inconvenient to provide one's self with two or three graham crackers and a stalk of celery. These with a drink of water and a little brisk exercise before an open window ought so far to divert the circulation from the brain as to enable one to fall asleep quickly. e. =The Dietetic Control of the Kidneys and Skin.=--The stimulation of excretion through the kidneys and skin may be an exceedingly important thing, particularly if one has just caught a cold and wishes to establish free excretion. The food which has a most clearly marked effect upon both kidneys and skin is the juice of the citrus fruits. These fruits, as they appear in our markets, are _lemons_, _oranges_ and _grape fruit_. All of these fruits are in a high degree wholesome as an addition to the dietary. Lemon juice is far more wholesome than vinegar in salads. The juices of lemons and oranges make most refreshing and deliciously cooling drinks in summer, and on occasions where one wishes _to get a strong stimulation of the kidneys and skin, he has only to drink large quantities of hot lemonade_. f. =The Dietetic Method of Curing a Cold.=--A whole _quart of hot lemonade_ may be taken on retiring after one has caught cold. The effect in such a case would be to cause a free sweating and copious urination. Both the action of the kidneys and the skin would tend to carry away from the system the effete materials that have been retained as a result of the cold.