74 THE POPULAR SCIENCE MONTHLY. 



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 sec- 

 ond 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 act- 

 ing on different bodies imparts velocity in the inverse ratio of their 

 masses, and it is therefore clear that, in order to make the large ma- 

 chine 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 prem- 

 ises of Miss Hardaker's second proposition, that male and female eat 

 in certain fixed proportions, that a certain fixed amount of that pro- 

 portion 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 addi- 

 tional 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 



