To be in what we English people call “good condition” there must be a correct proportion of the most important bodily constituents—viz., albumen, fat, and water. The first is the foundation of nerve, muscle, blood, etc., and in fact sustains the existence of the body. Relatively to albumen, water and fat may be viewed as auxiliaries, although they are indispensable in themselves. A proper condition of body requires that these three constituents shall be present in certain proportions, while the richer the body is in albumen the sounder it will be, and the fitter for work. On the other hand, any excess of fat or water will lessen its energies, and its power of repelling the action of influences likely to promote disease.

Of the evils of the increase of fat most people who suffer from it are only too conscious. But besides the more visible ones, they are usually poor-blooded, and consequently lacking in vital energy, while the fat diminishes the necessary space for the circulation of the blood and the respiratory organs. The first of these evils shows itself in flushing of the face when the circulation is quickened by exertion, and in the difficulty felt in the return of the blood from the lower parts of the body to the heart, which causes lassitude in the legs, and a tendency to varicose veins; while, if the circulation of water in the system be also impeded, dropsical swellings in the legs will ensue. The limitation of space due to fat hinders also the free play of the lungs, and the obese are disabled from exceptional exertion which necessitates fuller breathing than usual.

Thus every one wishing to preserve health and working capacity, must keep strict watch on the deposit of fat going on in the body; and all such symptoms must be taken as evincing a wrong system of living; and in order to stay its further accumulation and get rid of what is superfluous, recourse must be had to augmented action of the skin.

The increased percentage of water and fat in the system renders it also more liable to disease, more sensitive to cold, and disposed to chest affections in the winter. In addition, the working powers of the mind are sensibly lessened. Dr. Jaeger has discovered that their presence in excess can be tested by the specific gravity and the rapidity of the nervous action: and he has constructed an air-tight chamber where experiments may be conducted on the former, and a stop-watch tests the rapidity of the latter.

Not less interesting is Dr. Jaeger’s theory of the source of the emotions, which he places in the albumen in the bodily tissues, emanating in the form of subtile essences, which are opposed to each other in the effect they produce, and which may be distinguished as “salutary” and “noxious.” As a rule, the sanitary principle is fragrant, the noxious tainted and offensive. The odor may be most readily perceived in the hair of the head, and is more evident in the adult than the child. If the subject of the test be in a cheerful mood, the scent will be agreeable and sweet; but if sorrowful, depressed, or in pain, the scent will be disagreeable. This odor may be noticed in the anguish of fever, under the influence of terror, and exhales from the mouth and nose, and, as Dr. Jaeger has proved by experiment, from the brain as well.

These things Dr. Jaeger considers that the experience of many readers will confirm, and that they have great practical importance in connection with his system. The German names given to these odorous substances are Lust und Unlust Stoffe, substances of pleasure and dislike. The former are thought by the Doctor to be the healing powers of the body, which heighten all the vital actions and its powers of resistance against contagion of all kinds. Sheep’s wool in particular attracts these substances of pleasure, while the plant fibre favors the accumulation of the substances of dislike, with all their evil consequences. This last fact, which the German scientific medical world considers Dr. Jaeger has proved, is supposed to be of the greatest importance, as showing how to raise the resistibility of the human body against contagious disease. The observations made extend to diphtheria, cholera, typhus, smallpox, measles, whooping-cough, and influenza.

I have endeavored thus far to divest the subject, as far as possible, of scientific matter, so that the principle may be easily understood by those who have made no previous study of these or any kindred subjects, relating to the hygiene and sanitary management of the body. I will now turn to the more practical considerations of the materials and shapes of the clothing recommended.

Dr. Jaeger advocates the use of nothing but wool, both for clothing and also for the bed and bedding. No half-measures will answer; even the linings of coats and dresses must be of wool, and men’s collars, and even women’s stay-laces, must be of the same. The material which, after much consideration, he has selected, is what is called “stockingette web,” which is merely woollen yarn woven in an elastic manner, like jerseys and stockings, and the woollen and merino under-shirts and drawers, now in common use. The somewhat clumsy name “stockingette” owes its origin to the fact that there was no technical name for that kind of elastic weaving which is applied to stockings, and which was called into existence as a “piece” material by the fashion of wearing jerseys, three or four years ago. Dr. Jaeger considers this weaving porous and supple and more durable than flannel; while they feel more comfortable on the skin, and areless liable to shrink than flannel, when in the hands of the washerwomen.

No admixture of vegetable fibre should be admitted, and the practice of wearing a woollen shirt under a cotton or linen one, Dr. Jaeger considers enervating and weakening. Clothing should fit quite tightly to the skin, so as to allow of the least possible movement of air between it and the body; the second great rule being that it should be twice as thick along the middle line of the trunk, from the neck downwards, as at the sides or back. Another point for consideration is the number of garments to be worn one over the other. On this question Dr. Jaeger is of opinion that the clothing for men and boys should simply consist of a woollen shirt, woollen socks or stockings, cloth trousers fitting as closely as may be, and a cloth coat. The coat sleeves and linings should be of woollen, and these, as well as the trouser legs, when the latter do not fit tightly, must be closed against upward draughts by webbings sewn into them, and fitting tightly round the arms and ankles. No drawers are required, no waistcoat, and no overcoat; not even in the winter time, except when driving. Men’s coats must fit tightly up to the neck, and compactly to the figure, and all others must be laid aside as unsanitary. The coat must also be double-breasted, and like all the rest of the materials recommended, must be undyed, of the natural color, or treated with uninjurious fast dyes. The same rule applies to the trousers, which must fasten so as to continue the middle line of extra warmth. This rule has special application to those who desire to melt away superfluous fat, or those who are subject to disorders of the stomach or digestive organs.

The feet are to be covered with woollen socks, with a special division for each toe; or else one for the great toe, while the upper part of the boot must be of felt, and the lower part of felt or porous leather; the boot being kept thoroughly porous, so that the feet may be as cleanly and pure as the hands. The usual starched linen collar is substituted by one made of unstiffened white cashmere, or one of the wool in its natural hue. These collars can be obtained in every shape and style, stand up and turn-downs, and they are considered as the most comfortable that could possibly be devised, as well as preventions of throat disorders. The hat should be of felt, and no linings of leather nor linen are admissible. Instead of these a strip of felt should be used, or else the hat should be quite without lining, like a Turkish fez. The shellac used in stiffening hats is said to have an injurious effect, and those who are bald or threatened with baldness, or those who suffer from headaches, are especially advised to try the unstiffened sanitary hat and its woollen lining.