Man being an animal destined for an active and useful life, Providence has ordained that sloth shall bring with it its own punishment. He who passes nearly the whole of his life in the open air, inhaling a salubrious atmosphere, enjoys health and vigour of body with tranquillity of mind, and dies at the utmost limit allotted to mortality. He, on the contrary, who leads an indolent or sedentary life, combining with it excessive mental exertion, is a martyr to a train of nervous symptoms, which are extremely annoying. Man was not created for a sedentary or slothful life; but all his organs and attributes are calculated for an existence of activity and industry. If therefore we would insure health and comfort, we must make exercise--to use Dr. Cheyne's expression--a part of our religion. But this exercise should be _in the open air_, and in such places as are most free from smoke, or any noxious exhalations; where, in fact, the air circulates freely, purely, and abundantly. I am continually told by persons that they take a great deal of exercise, being constantly on their feet from morning till night; but, upon inquiry, it happens, that this exercise is not in the open air, but in a crowded apartment, perhaps, as in a public office, a manufactory, or at a dress maker's, where twenty or thirty young girls are crammed together from nine o'clock in the morning till nine at night, or, what is nearly as pernicious, in a house but thinly inhabited. Exercise this cannot be called; it is the worst species of labour, entailing upon its victims numerous evils. Good air is as essential as wholesome food; for the air, by coming into immediate contact with the blood, enters at once into the constitution. If therefore the air be bad, every part of the body, whether near the heart or far from it, must participate in the evil which is produced. It is on this account that exercise _in the open air_ is so materially beneficial to digestion. If the blood be not properly prepared by the action of good air, how can the arteries of the stomach secrete good gastric juice? Then, we have a mechanical effect besides. By exercise the circulation of the blood is rendered more energetic and regular. Every artery, muscle, and gland is excited into action, and the work of existence goes on with spirit. The muscles press the blood-vessels, and squeeze the glands, so that none of them can be idle; so that, in short, every organ thus influenced must be in action. The consequence of all this is, that every function is well performed. The stomach digests readily, the liver pours out its bile freely, the bowels act regularly, and much superfluous heat is thrown out by perspiration. These are all very important operations, and in proportion to the perfection with which they are performed will be the health and comfort of the individual.