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AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



weight is to be considered more frequent among men of distinction cannot be 

 determined until there is available a large number of records obtained, not 

 from the less-favored social classes, but from persons accounted as successful 

 merchants, bankers, and members of the learned professions. 



Brain-weight of Criminals. The observations of Manouvrier have 

 shown that among French murderers the brain-weight is similaf to that of the 

 individuals usually examined in the Parisian hospitals. In the same manner, 

 the observations on the brain-weight among the insane indicate, according to 

 the records of Boyd and others, that the insane as a class (the microcephalies 

 being of course excluded) are not characterized by a special brain-weight. 

 When, however, the insane are grouped according to the special diseases from 

 which they have suffered, it is evident that those in which the brain was con- 

 gested at death exhibit the higher weight, while those in which the pathological 

 processes caused destructive changes exhibit a low weight. The differences in 

 these cases are rather the results of disease than the cause of it. 



Brain-weights of Different Races. Concerning the weights of the brain 

 in different races there are no extensive observations which have been made 

 directly on the brain itself. Davis 1 has, however, determined the cranial capaci- 

 ties of a series of skulls belonging to different races, and the brain-weights as 

 calculated from these are as follows : 



1 Journal of the Academy of Natural Science, Philadelphia, 1869. 



