_Habit._—Nowhere is the effect of habit more conspicuous than in the matter of a daily evacuation of the bowels. There should be a fixed time every day for this, and the very best time is in the morning, directly after breakfast. Such a habit, once established, will enforce itself upon the attention and make regularity a necessity. It not infrequently happens that constipation is the result of irregularity in going to the toilet. The school-girl or woman gets up a little late, and, although she may feel the inclination to empty the bowels, she is able to defer it. If the movement is sufficiently large, one stool daily is sufficient, but where the stool is slight in quantity, there may be two or three during the day, entirely consistent with health, and in a run down state of the system there are apt to be several small movements rather than one full stool. So long as the stools are not watery, the individual may rest assured that there is no looseness of the bowels. Constipation should never be allowed to become chronic. It is, as has already been shown, the progenitor of myriads of the most serious diseases; and, after the bad habits of years have been established, it is one of the most obstinate of diseases to cure. In every case a good physician should be consulted at once, and the treatment should be persevered in until the cure is complete. It is a well-known fact that all medicines for this trouble lose their effect, the dose has to be increased, and a frequent change made from one laxative to another. When everything else fails, electricity may be resorted to. It is one of our most valuable remedies, since it brings about a cure through the toning up of the muscular walls of the intestine. The constant use of hot clysters to empty the rectum is one of the most pernicious habits; in this manner the bowel becomes overdistended and loses its tone, and the fecal mass is not sufficiently large to cause the distention of the rectum, which is the normal stimulus leading to the desire to defecate. =The Amount of Food Required.=—Food is required for growth and for repair; that is, to build up the organism and make good the loses sustained by physiologic processes, to maintain the heat of the organism, and to supply it with mechanical energy. It has become an established custom to compare the human body to a machine. Both derive their power from fuel; in both instances the potential energy of the fuel is transformed into kinetic energy or mechanical power which works the machine; in both cases the energy which is not used in work escapes in the form of heat.