_Horseback Riding_ is a mixed exercise, partly active and partly passive, the lower parts of the body being in some measure employed, while the upper parts in easy cantering are almost wholly relaxed. It is peculiarly suited to dyspeptics, from its direct action upon the abdominal viscera, the contents of which are stimulated by the continued agitation and succussion, consequent on the motion in riding. _Bicycling and Tricycling_.--While strongly recommending bicycling and tricycling to both men and women in health, those suffering from heart or lung affections, ruptures, scrofula, joint disease, or like maladies, should not indulge in them without medical sanction. For abdominal complaints, such as dyspepsia, congestion of the liver, constipation, and the like, the exercise is excellent. _Baseball_ is an essentially American game, which brings into play nearly all the muscles of the body. Its chief danger lies in being hit by the hard, forcibly pitched ball, and, for weak persons, in the violence of the exercise. _Football_ is a rough-and-tumble game, suited only to that class of boys and men, who, brimming over with animal life, take small heed of the accidents liable to occur. _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.