Page:Popular Science Monthly Volume 26.djvu/24

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14
THE POPULAR SCIENCE MONTHLY.

In somnambulism the brain is asleep, and this quiescent state of the organ is often accompanied, in nervous and excitable persons, by an exalted condition of the spinal cord, and then we have the highest order of somnambulic manifestations, such as walking and the performance of complex and apparently systematic movements. If the sleep of the brain be somewhat less profound, and the spinal cord less excitable, the somnambulic manifestations do not extend beyond sleep-talking; a still less degree of cerebral inaction and of spinal irritability produces simply a restless sleep and a little muttering; and when the sleep is perfectly natural, and the nervous system of the individual well balanced, the movements do not extend beyond changing the position of the head and limbs and turning over in bed.

The phenomena of catalepsy, trance, and ecstasy are also indicative of an independent action of the spinal cord, inasmuch as the power of the brain is not exercised over the body, but is either quiescent or engrossed with subjects which have made a strong impression upon it. Some of the manifestations of mind shown under such conditions are exceedingly interesting, and are altogether outside of the domain of cerebral consciousness.

But notwithstanding the fact that the sympathetic system and the spinal cord share with the brain the office of producing mind, there is no question that this lastnamed organ, immeasurably in man at least, transcends them in power.

The brain is by far the largest mass of nerve-substance contained in the body of any animal possessing a brain; indeed, it far exceeds in bulk and weight all the rest of the nervous system together. The researches of European observers give 49 ounces as the weight of the average brain of the white inhabitants of Europe—the maximum, that of Cuvier, being 6413 ounces, and the minimum, consistent with a fair degree of intelligence, 34 ounces. Webster's brain (allowance being made for disease which existed) weighed 6334 ounces. Dr. Abercrombie's 63 ounces, and Spurzheim's 55Jg ounces. The average of twenty-four American brains, accurately weighed by Dr. Ira Russell, was 52·06 ounces—the maximum 64 and the minimum 44·25 ounces. The same observer found the average full negro brain, as determined from 147 specimens, to be but 46·96 ounces.

The capacity of Daniel Webster's cranium was the largest on record, being 122 cubic inches. That of the Teutonic family, including English, Germans, and Americans, is 92 cubic inches. In the native African negro it is 83 cubic inches, and in the Australian and Hottentot but 75. The brain of the idiot seldom weighs over 23 ounces, and it is often much less than this. In one instance coming under my own observation, the weight of the entire brain was but 1412 ounces. Mr. Gore has related in the "Anthropological Review" the particulars of a case of microcephaly in which the brain weighed but 10 ounces and 5 grains. The subject, a female, though forty-two years of age, had