536 THE NERYOUS SYSTEM. 



mental functions are manifested in very different degrees. 

 Even in early childhood, before education can be imagined 

 to have exercised any influence on the mind, children 

 exhibit various dispositions each presents some predomi- 

 nant propensity, or evinces a singular aptness in some 

 study or pursuit ; and it is a matter of daily observation 

 that every one has his peculiar talent or propensity. But 

 it is difficult to imagine how this could be the case, if the 

 manifestation of each faculty depended on the whole of the 

 brain : different conditions of the whole mass might affect 

 the mind generally, depressing or exalting all its functions 

 in an equal degree, but could not permit one faculty to 

 be strongly and another weakly manifested. 3. The 

 plurality of organs in the brain is supported by the phe- 

 nomena of some forms of mental derangement. It is not 

 usual for all the mental faculties in an insane person to be 

 equally disordered ; it often happens that the strength of 

 some is increased, while that of others is diminished ; and 

 in many cases one function only of the mind is deranged, 

 while all the rest are performed in a natural manner. 4. 

 The same opinion is supported by the fact that the several 

 mental faculties are developed to their greatest strength at 

 different periods of life, some being exercised with great 

 energy in childhood, others only in adult age ; and that, 

 as their energy decreases in old age, there is not a gradual 

 and equal diminution of power in all of them at once, but, 

 on the contrary, a diminution in one or more, while others 

 retain their full strength, or even increase in power. 5. 

 The plurality of cerebral organs appears to be indicated 

 by the phenomena of dreams, in which only a part of the 

 mental faculties are at rest or asleep, while the others are 

 awake, and, it is presumed, are exercised through the 

 medium of the parts of the brain appropriated to them. 



These facts have been so illustrated and adapted by 

 phrenologists, that the theory of the plurality of organs 

 in the cerebrum, thus made probable, has been commonly 



