Persons who follow sedentary pursuits take but little bodily exercise, and it is incumbent upon them to find some substitute for the labour which was formerly demanded by Nature. Gymnastic and outdoor sports meet this requirement to a large extent. The hours of labour in almost all occu pations take up about one-third of the day, and after allowing a sufficient time for rest and sleep there remains a certain number of hours which may be devoted to recreation and amusement. The importance of devoting a portion of this time to regular bodily exercises must not be under-estimated, The variety of exercise is to some extent immaterial, whether it be walking or some other form of activity, so long as it is done with regularity. All who follow this advice will soon note the physical benefits derived. The various groups of muscles are brought into a condition of constant tension, although this varies in degree. This tension induces, a continuous irrita tion of the sensory nerves within the substance ol the muscles, and this irritation is transmitted through the spinal cord to the brain, where it is communicated to the nerve-cells. From these the impulses are sent back to various parts of the body, affecting particularly the blood-vessels and the heart. The arteries in the vicinity of the active muscles are dilated, and an increased amount of blood finds its way to the limbs which are in motion.
The heart is influenced in three ways. In the first place, the individual beats are lengthened ; secondly, they become stronger and more efficient ; and thirdly, the cardiac muscle is brought into a condition of tension. On this condition of alternating muscular and nervous activity depends the well-being of the body. liens sana in corpore sano (" A sound mind in a
sound body ") is a quotation which applies as well to-day as it did in antiquity. An unnatural mode of life, combined very often with insufficient exercise, has resulted in a loss of health to many persons, and the proper exercise of the body will restore a great many of these to a normal condition. In conclusion, it must be urged upon all who are healthy to cultivate a regular system of exercise as far as the spare time at their disposal allows, and if possible it should he carried out in the open air.
EXHAUSTION.—This term is applied to the feeling of general bodily and mental fatigue which usually follows severe bodily or mental exertions, prolonged sleeplessness, continued excitement, forced marches, athletic or sexual excesses, alcoholic indulgences, and all other influences which do harm to the body, such as hemorrhages and convulsive seizures. Enforced rest, and avoidance of the cause of the trouble, arc the principal curative measures which aid in restoring the normal condition of the system. Cool baths and sponging, fresh air with plenty of sunlight, and short walks arc also to be recommended. Exhaustion may usually he avoided by a sensible adherence to alternating periods of work and relaxation. A different cause, however, underlies those conditions of apparent fatigue which pre cede the appearance of a contagious disease, before the nature of the latter can be determined. These are merely the evidences of an infection, and are usually marked by pain in the joints, disinclination to any effort, depressed spirits, and other indefinite signs. In such cases it is well to call in a physician.