CHAP. X.] WEIGHT OF THE BRAIN. 261 



upon the cerebrum and cerebellum, the medulla oblongata and 

 mesocephale forming not more than one-tenth of the whole weight. 

 These parts exist in their highest state of development in man. 

 Their size does not appear to be regulated by the physical de- 

 velopment of the body, either in man or in the lower animals. 

 Thus the horse, although greatly exceeding the human subject in 

 the size of his body, has a brain considerably inferior. The largest 

 brain of a horse weighs, according to Scemmering, 1 Ib. 7 oz , but 

 the smallest adult human brain may be estimated at 2 Ibs. 5| oz. 

 Many other instances might be cited, of animals of great bulk, 

 with brains weighing considerably less than that of man. The 

 brains of the elephant and the whale, however, although inferior 

 to it in general organization, are absolutely heavier than that of 

 man. That of an elephant, dissected by Sir Astley Cooper, had a 

 weight of 8 Ibs. 1 oz. ; and Rudolphi found the brain of a whale, 

 75 feet long, (Balana mysticetus,) to weigh 5 Ibs. 10J oz. Yet 

 how inferior must be the development of the brain in these stu- 

 pendous animals relatively to the whole body, if, with their enor- 

 mous superiority of bulk, their brains exhibit so little excess of 

 weight over that of man ! 



Even among men there does not appear to be any fixed relation 

 between the bulk of the body and that of the brain. A large man 

 has by no means necessarily a large brain, and it oftens happens 

 that persons of small stature have the brain above the average size. 

 In women the brain is generally lighter than in men. Dr. John 

 Reid assigns an average difference of 5 oz. 1 1 dr.. in favour of 

 the male brain. Yet this difference is scarcely proportionate to 

 the general inferiority of organization and of size of the female 

 to the male. 



It is impossible to explain the great superiority of the human 

 brain, both in organization and in the absolute quantity of nervous 

 matter which it contains, without admitting its connexion with the 

 mind, and the influence exerted upon its nutrition and growth by 

 that immaterial principle. The men of greatest intellectual power 

 are those who possess the largest brains. Cuvier's brain, as stated 

 by Tiedemann, weighed 4 Ibs. 11 oz. 4 dr. 30 grs. troy; and that of 

 Dupuytren 1 oz. 4 dr. 30 grs. less. On the other hand, the brain of an 

 idiot weighs scarcely more than that of the horse mentioned above. 

 Tiedemann found the brain of an idiot, fifty years old, to weigh 

 1 Ib. 8oz.4drs. ; and that of another, forty years old, 1 Ib. 11 oz. 

 4 drs. In advanced age, when the mental faculties have declined, 

 the brain generally experiences a decrease of size; there are many 



