Page:Popular Science Monthly Volume 21.djvu/82

74 ounces without such result" (page 578). Here are two brains precisely of the same quality, one thirty-seven ounces the other thirty-one, an absolute difference of six ounces. Yet these six ounces represent just nothing. Indeed, give the woman thirty-four ounces and leave the man thirty-seven, his three ounces more are simply a minus: thirty-four is rational thought, thirty-seven irrational. In this instance a small amount of matter represents more power than a large amount. It would seem that the true law must be sought elsewhere than in the grocer's scale.

But the impelling force which Miss Hardaker omits in her former statement is supplied in her next assumption: "All human energy is derived from food. Man eats more than woman because his larger size requires him to do so, a larger proportion of nourishment is sent to his brain; hence men think more than women." A look backward at our elementary law of physics will show that Miss Hardaker's second conclusion is as weak as her first. To repeat that portion of our law which bears upon this argument, we find that the same force acting on different bodies imparts velocity in the inverse ratio of their masses, and it is therefore clear that, in order to make the large machine run as fast as the small one, fuel must be supplied to the former more freely. The explosive force that sends the tiny rifle-ball at the rate of twenty miles a minute could not overcome the inertia of the missile discharged from the Krupp gun; a proportional force to each would send each just the same distance. Now, granting all the premises of Miss Hardaker's second proposition, that male and female eat in certain fixed proportions, that a certain fixed amount of that proportion goes to nourish relatively proportioned brains, the only logical conclusion is that the larger brain, supplied with more blood, would in a given time do heavier work, but not more work, than the smaller one supplied with less blood. Under these circumstances the momentum of the larger brain would be greater than that of the small brain; their velocities equal. Without his extra supply of blood, man's brain could never overtake woman's in velocity; indeed, without this additional stimulus it might not be able to move at all. The theory that the smaller brain is propelled more easily, might explain the quickness of perception and of fancy which, according to Miss Hardaker, are womanly traits.

Such reasoning, however, is at best mere theorizing, for it applies the simple laws of mechanics to the intricate and so far inexplicable structure of the brain, making no allowance for complications which would divert the action of the law. It may be true that blood is the primary motor of the brain; but there are many other elements besides the size of brain and body, or even the amount of food assimilated, which measure the quantity of blood sent to the brain. The problem is by no means, as Miss Hardaker has tried to make it, an easy sum in simple proportion which the school-boy may solve standing on one