Light and Heavy Gymnastics.—For wet weather, and when outdoor exercise is not practicable, gymnastics are most advisable. Boys and girls, at the age of fifteen or sixteen, often shoot up and become tall and lanky; they want filling out, and are troubled with growing pains. Even men, when tall and thin, are seldom very erect, their muscles are too weak; and there is only one way of overcoming this weakness—by exercising them. Nothing more is wanted than a pair of very light Indian clubs, a pair of light wooden dumb bells, a long wooden rod, and a pair of wooden rings,—the last for combined exercises. Indeed, a systematic motion of the body itself, without any extra artificial resistance, is quite sufficient for the purposes of physical education. In nearly all our large cities are found gymnasia, provided with competent instructors, and every facility for both light and heavy gymnastics. Exercise in a gymnasium is open to the objection of being too brief and too severe, and of simply causing an increase of muscular development. Besides, it is generally unequal in its results, being better adapted to the cultivation of strength in the upper extremities and portion of the body than in the lower. Nevertheless, during inclement weather, or with persons in whom the muscles of the arms and chest are defective, moderate gymnastic exercise is far better than no exercise.—Compiled. (Mostly from "The Influence of Exercise" in The Book of Health.)

THE SKIN.

THE HAIR (p. 52).—Baldness, and its Causes.—Various reasons are assigned for the baldness which is so prevalent among comparatively young men in our country. One writer says: "The premature baldness and grayness of the Americans as a people is in great measure owing to the nonobservance of hygienic rules, and to excess of mental and physical labor in a climate foreign to the race." Others attribute it to the close unventilated hats commonly worn by men. Dr. Nichols, in the Popular Science News, gives his opinion thus:

"In our view, it is largely due to modern methods of treatment of the hair and scalp. The erroneous idea prevails, that the skin which holds the hair follicles and the delicate secretory organs of the scalp must be kept as 'clean,' so to speak, as the face or hands; consequently young men patronize barbers or hairdressers, and once or twice a week they have what is called a 'shampoo' operation performed. This consists in a thorough scouring of the hair and scalp with dilute ammonia, water, and soap, so that a heavy 'lather' is produced, and the glandular secretions, which are the natural protection of the hair, and promotive of its growth, are saponified and removed. No act could be more directly destructive of a healthy growth of hair than this….Women do not shampoo or wash the hair as often as the other sex, and consequently they are in a large degree exempt from baldness in middle life. It is true, however, that many women in cities make frequent visits to the hairdressers, and subject their tresses to the 'scouring' process. If this becomes common, it will not be long before baldness will overtake the young mothers as well as the fathers, and the time will be hastened when even children will have no hair to destroy with ammonia or other caustic cosmetics.

"The advice we have to offer to young men and maidens is,—let your hair alone; keep at a safe distance from hair-dressing rooms and drug shops, where are sold oils, alkaline substances, alcoholic mixtures, etc., for use upon the hair. They are all pernicious, and will do you harm. The head and hair may be washed occasionally with soft, tepid water, without soap of any kind. As a rule, the only appliances needed in the care of the hair are good combs and brushes: and they should not be used harshly, so as to wound the scalp. Avoid all 'electric' and wire-made brushes. No electricity can be stored in a hairbrush: if it could be, it is not needed."

Sudden Blanching of the Hair from Violent Emotions.—The color of the hair depends mainly upon the presence of pigment granules, which range in tint from a light yellow to an intense black. A recent investigator has succeeded in extracting the coloring matter of the hair, and has found that all the different shades are produced by the mixture of three primary colors—red, yellow, and black. "In the pure golden yellow hair there is only the yellow pigment; in red hair the red pigment is mixed with more or less yellow, producing the various shades of red and orange; in dark hair the black is always mixed with yellow and red, but the latter are overpowered by the black; and it seems that even the blackest hair, such as that of the negro, contains as much red pigment as the very reddest hair." Hence, "if in the negro the black pigment had not been developed, the hair of all negroes would be a fiery red."—DR. C. H. LEONARD. The Hair: Its Diseases and Treatment.

The gradual disappearance of this pigment causes the gray or white hair of old age. This natural change in color does not necessarily denote loss of vitality in the hair, as it often continues to grow as vigorously as before it began to whiten. Cases of sudden blanching of the hair from extreme grief or terror are often quoted,—those of Sir Thomas More and of Marie Antoinette being well-known instances in point. An interesting circumstance has been discovered with regard to such cases, namely, that the change of color is not dependent upon the disappearance of the pigment of the hair, which always takes place slowly, but upon the sudden development in its interior of a number of air bubbles, that hide and destroy the effect of the pigment, which itself remains unaltered. Dr. Landois mentions the case of a German printer whom he attended, at a hospital, in the summer of 1865.

This man had long been intemperate in his habits, in consequence of which he was seized with delirium tremens. The delirium, as is usual in such cases, was of an extremely terrifying nature, and lasted four days. On the evening of the fourth day the hair was unaltered, but on the morning of the fifth the delirium had disappeared, and his hair, which previously was fair, had become gray. It was examined with the microscope, when it was found that the pigment was still present, but that the central streak of each was filled with air bubbles.

How this superabundance of air finds its way into the hair in these cases of sudden blanching, physiologists have not yet been able satisfactorily to explain.—In this connection, however, it may be observed that air bubbles exist, more or less, in all hair, mingled with the pigment granules.

The feathers of birds owe their bright colors to an oily secretion corresponding to the pigment in hair, and microscopical observation has revealed the fact that when these colors fade the oily secretion disappears, and is replaced by air. That extreme terror may blanch feathers as well as hair is shown in the case of a poor little starling, which upon being rescued from the claws of a cat became suddenly white.