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.