Page:American Journal of Sociology Volume 1.djvu/449

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SCOPE AND METHOD OF FOLK-PSYCHOLOGY.
437

presumed. It is true that the cerebral lobes are the seat of consciousness; but the brain is no more essential to intelligence than is the circulation, or digestion, or the liver. Intelligence is the mediation of action, and all organs and tissues which cooperate in forming an association, are equally important with the brain. The five heaviest brains recorded by Topinard are those of Tourgenieff (2020 gr.), a day-laborer (1925 gr.), a brickmason (1900 gr.), an epileptic (1830 gr.), and the illustrious Cuvier (1830 gr.) French anthropologists have reckoned the average brain-weight as 1360 grammes, and the inferior limit of brain-weight compatible with reason as 1000 grammes. But when their idol Gambetta lately willed them his brain and died, they were mortified to find that it weighed only 1100 grammes—just 100 grammes above the point of imbecility. These facts merely show that preconceptions were wrong, and that anthropology has made itself more scientific in this regard. Gross anatomy of the brain, especially in the hands of surgeons, and fine anatomy, in the hands of neurologists, have established important laws of growth and of mental pathology, but no anthropologist can venture to say of a series of brains which are male and which female, which Chinese and which German. The whole matter of the relation of intelligence to brain-weight, and of the nature and quantity of energy which is a function of this organ, is, indeed, fundamentally a question of physiological chemistry. The assumption that capacity for muscular work is in direct proportion to the mass is approximately correct; but the assumption that capacity for mental work is in proportion to the mass of nerve substance is a gross error, as anthropologists now very well know. Physiologists are, indeed, compelled to assume a different principle of metabolism in the nerves from that of the muscles, though the nerves have thus far eluded inquiry in this direction.

Examination of the brain capsule and calculation of its capacity (craniometry), and superficial measurements upon the head of the living (cephalometry), have, in the nature of the case, still more attenuated connections with the development of