Everything tends to prove that man was destined to lead a life of bodily action. His formation--his physical structure generally, and that of his joints particularly--his great capacity for speed and laborious exertion--the Divine injunction, that "he shall live by the sweat of his brow"--the bodily imbecility and enfeebled health invariably consequent upon sedentary habit--all go to prove that he was destined to lead a life of physical activity. Most people are apt to despise many of the aids to health, because of their very simplicity. A sensible Dervish, in the Eastern allegory, well aware of this weakness of human nature to despise simple things, and venerate those they do not understand, when called to the Sultan to cure him of a disease, did not dare to simply advise him to take exercise; but he said to him: -- "Here is a ball which I have stuffed with certain rare and precious medicines. And here is a bat, the handle of which I have also stuffed with similar medicines. Your Highness must take this bat and with it beat about this ball, until you perspire very freely. You must do this every day."  His Highness did so; and, in a short time the exercise of playing at bat and ball with the Dervish cured the Sultan's malady. But it should be remembered that there are a great many cases where medicines must be given to assist nature, besides the employment of exercise to facilitate the recovery of the patient.

Nevertheless, exercise is one of the chief aids of all others I must recommend to be adopted as eminently essential for the remedying of bad health, and of preserving that which is already good. It is impossible for a healthy adult to be otherwise than active in body or mind, or both; while it may be asserted, with abundant reason, that laziness is actually a disease, dependent on some abnormal condition of the organism. A variety of social circumstances may operate to produce an indolent disposition of mind and inactive habit of body, but these also produce a primary condition of ill-health.

The function of respiration, by which the blood is vitalized, and the nutrition of the muscular structure, on which depend all the motive power or strength of the system, are intimately connected with the circulation of the blood, and this with active exercise. Without this, there must be unhealthy accumulation somewhere; and, as the larger arteries are not permanently dilatable, while the veins and capillary arteries are so, this accumulation or congestion must take place in the veins and capillary or hair-like arteries.

When the circulation is feeble from lack of bodily exercise, or other cause, the blood creeps sluggishly along the minute vessels composing the elementary tissue of the body; these veins and capillaries become gorged, which engorgement operates as a still further impediment to the free flow of the blood. The blood, when not circulated with due energy through the ultimate tissues, becomes deteriorated in quality, and so, in turn, fails to supply that proper nutrition upon which, according to its degree of purity, all the tissues and functions of the body depend. If the propelling power arising from breathing pure air and using active bodily exercise is not sufficiently energetic, the circulation through the elementary tissue is so slow that the blood loses its healthful arterial hue before it has reached the extremities of the hair-like arteries; and thus that part of the tissue which ought to be filled with arterial blood is gorged only with black venous blood, from which the proper secretion necessary to the nutrition of the body, cannot be separated, either in due abundance or of a healthy quality. Hence, if this state of congestion be permitted to exist from lack of active exercise and consequent free respiration, so as to vitalize the blood, there must needs be a speedy wasting of flesh, and all the other phenomena of consumption or any other disease. The strength of the system is intimately connected with the circulation of the blood, as stimulated in its flow by means of active bodily exercise and pure air.

This principle is well illustrated in the effects of gymnastics and training, by which the muscles of any part of the body are remarkably invigorated by regular systematic exercise. People of all trades and occupations find those parts of the muscular system which are habitually the most exercised to be the most powerful.

For healthful purposes all that is necessary is, any way, to exercise all parts of the body to a degree of fatigue without exhaustion; that is, to a degree which will insure an energetic circulation of the blood throughout the entire economy. All exercises, however, to secure their full benefit, should be coupled either with some object of utility or amusement, otherwise the mind is apt to labor adversely to the body.

When I say that exercise is what is wanted to restore to health the weak and languid, I mean that it is not so much exercise that is wanted as the exhilarating effect which the enjoyment of exercise produces. A man who exercises half an hour unwillingly in his wood-shed, is not benefited in the degree one is who takes an hour's walk for pleasure through a beautiful country.

It is the enjoyment of exercise in which consists its chiefest excellence. It is the diversion of the mind from the ailments of the body. The invalid is by this drawn away from himself.

What can better accomplish this object than amusement? Laughter and lively talk may be said to be a species of exercise -- mental exercise -- which is very often as beneficial to an invalid as physical exercise. Anything that will induce a fit of laughter must have an influence in promoting an active circulation of blood, and, as we have seen, it is necessary to health that the blood should be duly aerated and flow with energy through the system. Whatever means may be employed to give rapid circulation to the blood must be conducive to health. I believe, then, most fully in using all proper means of amusement which will cheer the invalid, and thus be a mental stimulus or auxiliary to the preservation and restoration of health.

So, not only are amusements which afford exercise to the mental faculties useful, but occupation -- some useful business pursuit, which requires, and hence secures, attention and labor during several hours of each day -- is absolutely essential to the high sanitary condition of the body, for nothing else will insure so constant, regular, and equally divided exercise for both mind and body.