188 



Brain of the Negro compared with that of 



[Jan. 



absolute magnitude of the brain, but in regard, also, to " the bulk and 

 thickness of the cerebral nerves, and likewise to the degree of perfec- 

 tion in its structure." From his researches. Dr. Tiedemann draws the 

 following conclusions : — 



" ]. The brain of a new-born child is relatively to the size of the 

 bod}^ the largest: the proportion is I : 6. 



" 2. The human brain is smaller in comparison to the body the 

 nearer man approaches to his full growth. In the second year the 

 proportion of the brain to the body is as 1 : 14 ; in the third, 1 : 18 ; in 

 the fifteenth, 1 : 24. In a full-grown man between the age of tv.en- 

 ty and seventy years, as 1 : 35 to 45. In lean persons the proportion is 

 often as 1 : 22 to 27; in stout persons as I : 50 to 100, and more. 



"3. Although Aristotle lias remarked that the female brain is ab- 

 solutely smaller than the male, it is nevertheless not relatively smaller 

 compared Willi the body ; for the female body is in general iighfer 

 than that of the male. The female brain is for the most part even 

 larger than the male, compared wilh the size of the body. 



" The different degree of susceptibility and sensibility of the nervous 

 system seems to depend on the relative size of the brain as compared 

 with that of the body. Children and young people are more suscepti- 

 ble, irritable, and sensible than adults, and have a relatively larger 

 brain. Thin persons are more susceptible than stout. In diseases 

 which affect the nourishment of the body the susceptibility in- 

 creases as the patients grow thinner. The susceptibility and sensibi- 

 lity decreases, on the other hand, with persons recovering from a long 

 illness, gradually as they regain their strength. The degree of sensi- 

 bility in animals is also in proportion to the size of the brain. Mam- 

 malia and birds have a larger brain and are more susceptible than am- 

 phibious animals and fishes. I propose to go into this subject on ano- 

 ther occasion, as it would at present take me too far from my immediate 

 object." 



Very few observations have been actually made of the actual and 

 relative weight of the brain of the negro; and Dr. Tiedemann has, 

 therefore, had recourse to ascertaining the relative contents of the 

 cavity of the skull ; and he gives tables of the results obtained from a 

 number of negro, European, Mongolian, American, and Malayan skulls, 

 thus examined. The general conclusion is, that the cavura cranii of 

 the negro is not relatively smaller than that of the European and 

 other human races. 



He then proceeds to show, on the authority of the most intelligent 

 and accurate travellers in Africa, that the general characters and 

 marks of the Ethiopian race usually giv en, apply only to a very 



