330 MENTAL FACULTIES. 



M. Bourgery 1 found, that the mean weight of the encephalon being 

 20393-5 grains troy, the cerebral hemispheres weigh 16940-46 grains; 

 the cerebellum, 2176*7 grains ; the cephalic prolongation of the cere- 

 bro-spinal axis, 1312-2 grains ; of which the optic thalami and corpora 

 striata make 879-9 grains ; the medulla oblongata with the pons Varolii 

 432-2 grains ; and the spinal cord 710-1 grains. Hence, in man, the 

 cerebral hemispheres include a nervous mass, which is four times greater 

 than the rest of the cerebro-spinal mass ; nine times greater than the 

 cerebellum ; thirteen times greater than the cephalic stem of the spinal 

 cord ; and twenty-four times greater than the spinal cord itself. 



It has been the general belief, that the brain of the negro is inferior 

 to that of the white variety of the species ; but certain observations of 

 M. Tiedemann led him to the belief, that there is no perceptible differ- 

 ence either in its average weight or average size in the two varieties, 

 and that the nerves compared with the size of the brain are not larger 

 in the former than in the latter. In the external form of the brain of 

 the negro a very slight difference only could be traced ; and he affirmed 

 further, that there is absolutely no difference in its external structure, 

 nor does the negro brain exhibit any greater resemblance to that of the 

 ourang outang than the brain of the European, excepting, perhaps, in 

 the more symmetrical disposition of its convolutions. Tiedemann's 

 observations were made, however, upon few subjects ; and his own facts 

 do not bear out all his deductions. He admits, that the anterior part 

 of the hemispheres was something narrower than is usually the case in 

 Europeans, " which," says Dr. Combe, 2 "as the anterior portion is 

 the seat of intellect, is really equivalent to conceding that the negro is 

 naturally inferior in intellectual capacity to the European !" M. Tiede- 

 mann established that the average capacity of the Ethiopian skull is 

 somewhat less than that of the European, and that a large sized skull is 

 considerably less frequent among them than among any other races of 

 mankind. 3 



The following table, drawn up by Dr. Morton, 4 exhibits the absolute 

 capacity of the cranium or bulk of the brain in cubic inches, obtained 

 by filling the cavity of the crania with leaden shot, one-eighth of an 

 inch in diameter, in different races and families of man. 5 It sufficiently 

 exhibits how little can be judged, in this manner, of their relative intel- 

 lectual aptitudes. 



1 Lond. Med. Gaz., Jan., 1845, p. 462. 



2 Phrenological Journal. No. liv.,Dec., 1837. 



3 Brit, and For. Med. Rev.,'for Oct., 1839, p. 379. 



4 Catalogue of Skulls of Man and the Inferior Animals in the collection of Samuel George 

 Morton, M.D., &c., 3d edit., p. viii., Philad., 1849. 



6 For the ingenious process invented by Mr. J. S. Phillips, of Philadelphia, by which these 1 

 measurements were taken, see Dr. Morton's Crania Americana, p/203, Philad. and Lond., 

 1839. 



