Page:Popular Science Monthly Volume 29.djvu/341

Rh fortunate brothers, but must be a sober woman after she has entered her teens. It seems as if the battle of modern life (at least of modern city life) was a battle of the nerves. "From nursery to school, from school to college, or to work, the strain of brain goes on, and strain of nerve—scholarships, examinations, speculations, promotions, excitements, stimulations, long hours of work, late hours of rest, jaded frames, weary brains, jarring nerves all intensified by the exigencies of our school and city life." The worst of the mischief is, that this strain falls most of all upon those from nature and circumstance least able to bear it—upon our women. Public opinion frowns upon their exercising like men. Yet, with a nervous system more sensitive than man's, they need the very exercises (out-of-doors) which, by a mistaken public sentiment, they are often forbidden to take. The healthy house-work is often deputed to a servant either because too hard for our American girls, or too much beneath them.

Of the five agents of health—exercise, food, air, sleep, and bathing—exercise, to a certain extent, regulates the demand for the other agents. The muscles, when fully developed, constitute about a half of the full-grown body. The muscular contractions act upon the blood. The blood is the life-stream, carrying the atoms of nourishment to every part of the body, and receiving the waste particles which have already done their work. This process of depositing building substance and receiving waste matter goes on according to a law. This law, called, from its discoverer, the law of Treviranus, is—"Each organ is, to every other, as an excreting organ. In other words, to insure perfect health, every tissue, bone, nerve, tendon, or muscle, should take from the blood certain materials and return to it certain others. To do this, every organ must or ought to have its period of activity and rest, so as to keep the vital fluid in a proper state to nourish every other part." So that, if we give to the muscles their share of labor, as indicated by the ratio which they bear to the whole body, according to this law, we ought to give a large proportion of our waking hours to their use. But there are certain involuntary muscles doing their work all the time, night and day. In our usual vocations, too, how T ever confining they may be, we are obliged to take a certain amount of muscular exercise. Consequently, in the really necessary work of any ordinarily busy person, the muscles do have a fair share of exercise. Still, there are a number of muscles which are used almost exclusively, so that other muscles, with their connecting tendons, bones, and nerves, fail, from sheer neglect, to contribute to the health of the whole body. How many women exercise fully the large muscles of the back and loins, or the muscles of the abdomen? Women who wash, or those who work in field or garden. Yet these important muscles, when used, contribute much not only to the health of the body in general, but also to the vigor of the organs lying underneath