And now for the people who do not get enough exercise. In the armies of King Cyrus it was the law that every man was required to sweat once every twenty-four hours, and that is still the law for every business man and office-worker and writer of books. There is no substitute for it, and there is no health without it. I have heard Dr. Kellogg say that the modern woman sends out her health with her washing, and I have heard the leisure class ladies at the Sanitarium discuss this cryptic utterance and wonder what he meant by it. I know that there is use telling leisure class ladies what exercise at the wash-tub would do for their abdomens and backs. I will only tell them that unless they can find some kind of vigorous activity which keeps them in a free perspiration for an hour or two each day, they will never be really well, and will never bear children without agony and abortion. For myself, I have found that the minimum is three or four times a week. Unless I get that much hard exercise I am soon in trouble. So my advice to the business man is to take off his coat and collar and turn out and help his truck-man; my advice to the white collar slave is to get a part-time job, and dig ditches the rest of the time. To the man who has cares which pursue him, and likewise to the ardent student and brain-worker, I say that they should find, not merely exercise, but play. The distinction between the two things is important. There can be play that is not exercise, for example cards and chess; and, of course, there can be exercise that is not play. What you must have is something that is both play and exercise; something that not merely causes your heart to beat fast, and your lungs to pump fast, and your sweat glands to throw out poisons from your body, but something that fully occupies your mind and gives your higher brain centers a chance to relax. Our civilization has very largely destroyed the possibility of play and the spirit of play. We civilized people no longer know what play is, and regard the desire to play as something abnormal--a form of vice. We allow children to play after school hours, and on Saturdays; but for grown-up, serious-minded men and women to want to play would be almost as disreputable as for them to want to get drunk. What could foe more pitiful than the spectacle of tens of thousands of men crowding into our baseball parks and amusement fields to watch other men play for them! Imagine, if you can, a crowd of people gathering in a restaurant or theater to watch other people _eat_ for them! Imagine yourself a man from Mars, coming down to a world with so many people in want, and finding whole classes of men forbidden to do any work, under penalty of disgrace, and compelled, in order to exercise their muscles, to pull on rubber straps and lift weights and wave dumb-bells and Indian clubs in the air--methods of expending their muscular energy which are respectable because they accomplish nothing!