"Strength is health" has become a favorite phrase. But, like many common saws, it is an error. Visit the first half-dozen circuses that may come to town, and ask the managers whether the cannon-lifter or the general performer has the better health. You will find in every case it is the latter. Ask the doctors whether the cartmen, who are the strongest men in the city, have better health than other classes, who, like them, work in the open air, but with light and varied labor. You will not find that the measure of strength is the measure of health. Flexibility has far more to do with it. Suppose we undertake the training of two persons, of average condition. They have equal strength,--can lift four hundred pounds. Each has the usual stiff shoulders, back, and limbs. One lifts heavy weights until he can raise eight hundred pounds. Inevitably he has become still more inflexible. The other engages in such exercises as will remove all stiffness from every part of the body, attaining not only the greatest flexibility, but the most complete activity. Does any intelligent physiologist doubt that the latter will have done most for the promotion of his health? that he will have secured the most equable and complete circulation of the fluids, which is essentially what we mean by health, and have added most to the beauty and effectiveness of his physical action? With heavy dumb-bells the extent of motion is very limited, and of course the range and freedom of action will be correspondingly so. This is a point of great importance. The limbs, and indeed the entire body, should have the widest and freest range of motion. It is only thus that our performances in the business or pleasures of life become most effective. A complete, equable circulation of the blood is thereby most perfectly secured. And this, I may remark, is in one aspect the physiological purpose of all exercise. The race-horse has a much more vigorous circulation than the cart-horse. It is a fact not unfamiliar to horsemen, that, when a horse is transferred from slow, heavy work to the carriage, the surface-veins about the neck and legs begin at once to enlarge; when the change is made from the carriage to the cart, the reverse is the result.