76 THE POPULAR SCIENCE MONTHLY. 



for its nourishment, but the forces which effect this nourishment are 

 not easily turned in other directions, and it is, therefore, a natural se- 

 quence that the body must dwindle as the power of the mind increases. 

 The savage Teutons, whose great bodies affrighted the Romans of 

 Caesar, have become the civilized possessors of less bulk and more 

 knowledge. Human energy appears not to be harmonious, but to run 

 in grooves. Thought produces thought, and the energy once sent to 

 the brain is the direct cause of a new demand for supplies. In like 

 manner, the arm that is developed by work needs a larger amount of 

 food for its maintenance. This is the explanation of the historic fact 

 that physical and mental powers have never been proportionally culti- 

 vated, but always at the expense of each other. The profound thinker 

 and the superior pugilist are rarely united. 



But, even if it is true that the larger and healthier physique affords 

 more blood for brain-use, it does not follow that the larger the supply 

 the greater the amount of brain- work possible. The argument assumes 

 that the brain has no limit to its activity except in the quantity of 

 blood that ban be prepared for it. But it needs no scientific educa- 

 tion to know that there are other influences which limit the thinker's 

 activity, and that these limitations are somewhere in the mysterious 

 recesses of the brain, or in the forces of which the brain is the organ. 

 The physical health of the brain-worker may be perfect, his digestion 

 unimpaired, his power to assimilate food the same, and yet he may not 

 be able to concentrate his thoughts or carry on a complicated train of 

 reasoning. The defect is not in his body that is as healthy as ever ; 

 nor is it in any of the processes of blood-making these go on as be- 

 fore. The trouble lies in the brain itself, whose capacity for work 

 is measured by some hidden standard of its own, and which gives 

 warning when a cessation of brain-work is imperative. The body is a 

 furnace whose power of consuming fuel is greater than the capability 

 of its boiler the brain to generate power. To kee]3 the latter in 

 good working condition, something more is necessary than building 

 and feeding the fires. A supplementary but' important consideration 

 is, whether the steam beyond a certain point will not be productive of 

 unpleasant consequences in the form of an explosion. 



In the discussion of the collateral question, that of the effect of 

 maternity on brain-power, Miss Hardaker's scientific logic takes its 

 most amusing form. " The necessary outcome of absolute intellectual 

 equality of the sexes," she says, "would be the extinction of the human 

 race. For, if all food were converted into thought in both men and 

 icomen, no food tchatever coidd be appropriated for the reproduction 

 of species " ( page 583). What Miss Hardaker really means by this last 

 highly scientific axiom it is impossible to guess. She can not mean 

 that, as all food is converted into thought in men, women must cease 

 to be mothers in order to imitate his food-conversion. Whatever Miss 

 Hardaker may intend by her impossible supposition, the fact that ma- 



