BRAIN WEIGHTS AND INTELLECTUAL CAPACITY. 247 



the same as that of the skull of Joachim, an imbecile six feet nine 

 inches in height, with a brain weight of 61.2 ounces, whereas Spurz- 

 heim's brain weighed only 55 ounces. 



Whoever has examined heads in the dissecting room of a medical 

 college knows that, except in rare cases of disease, the brain does 

 not fit the skull, but is surrounded by three membranes and a watery 

 fluid; and this liquid, it has been ascertained, is generally sufficient 

 to admit of its performing certain movements. 



There can be no doubt that the brain moves in the skull, changing 

 its position, according to the laws of gravitation, in much the same 

 way as the lungs, heart, and liver do in the body. It has been 

 observed many times to move, as well as to pulsate, when exposed to 

 view during the life of the individual. It is subject to two regular 

 and constant motions — one produced by the arteries, the other by 

 respiration. It has also a third motion, discovered and described by 

 Dr. M. Luys, who stated, in a paper read before the Academy of 

 Medicine of Paris, that " the brain is subject to certain changes of 

 position, dependent on the attitude of the body. Thus, if a man lies 

 on his back or side, or stands on his head, the brain undergoes certain 

 changes of position in obedience to the laws of gravity; the move- 

 ments take place slowly, and the brain is five or six minutes in 

 returning to its previous position." From these anatomical data 

 M. Luys deduced some interesting and practical conclusions, by 

 which he explained, for example, the symptoms of vertigo which 

 feeble persons experience when suddenly rising from a horizontal 

 position. He suggested whether the pains of meningitis may not be 

 due to an interference with these normal movements, and urges the 

 value of giving the brain the change produced by a horizontal posi- 

 tion at night. 



The average cranial capacity is admitted to be 96 cubic inches in 

 England and 94 in New York; and it is to the unusual quantity of 

 fluid of some cases, and to the extraordinary thickness of the skull 

 in others, that we are to attribute the frequent discrepancy between 

 the external dimensions and the size of the encephalon. Daniel 

 Webster's cranial capacity was 122 cubic inches, yet his brain 

 of 53.5 ounces was just what George Combe has laid down 

 as the average weight for an adult man. Water and lymph, 

 we are told, filled the skull. Professor De Morgan's head, almost 

 free from hair, measured 24.87 inches in circumference, and 

 the dimensions were all those of a very large head, sufficient to 

 contain from 65 to TO ounces of brain, yet his brain weighed only 

 52.75 ounces, or little, if at all, above the average in the cold parts 

 of the temperate zones. De Morgan was sixty-five years of age when 

 he died. He was much emaciated, and " the brain was distinctly 



