Mr Nasmyth on the Human Mouth. 176 



naturalists to consider themselves warranted in regarding it as 

 a feature of approximation to the monkey tribe, although its 

 good condition is nothing more than a feature of healthy de- 

 velopment. The capabilities of this section of the mouth 

 being limited simply to that of comminution, or grinding, it is 

 not so much subject to the effects of abuse as the anterior 

 portion of the dental range. Perhaps the only abuse of it is, 

 that of exercise on food, calculated to wear away the gi'inding 

 surfaces of the teeth. The Hind^, the ancient Egyptian, and 

 others, present examples of these surfaces being entirely worn 

 away ; and even of the teeth in the anterior and median por- 

 tions of the mouth being reduced to truncated forms. The 

 cause of this peculiar effect appears to be the roughness and 

 grittiness of their food, and, in some cases, the almost exclusive 

 consumption of that of a vegetable character. This is a power- 

 ful reason why man ought to be considered an omnivorous 

 animal. 



Notwithstanding all I have said in favour of the more per- 

 fect development of the mouth in the rude and uncivilized 

 tribes, they are, nevertheless, not altogether exempted from 

 the ordinary diseases of the teeth. Independent of the habits 

 I have referred to as affecting the arrangement of their teeth, 

 and the development of their jaws, natural decay and disease 

 occur, which we may refer to the state of health of the parents, 

 the period of procreation, the circumstances under which their 

 systems are at the time of production, and the inadequate na- 

 ture of nourishment, more especially in their early stages of 

 existence. The general correctives of all these evils of develop- 

 ment are exercise of all the energies, both of body and mind — 

 residence in a healthful climate, and pure air, and a due supply 

 of wholesome and nourishing animal and vegetable food, — not 

 only in regard to individuals, but to succ'essive generations. 

 Combe remarks that no object can be presented to the philo- 

 sophic mind more replete with interest than an inquiry into 

 the causes of the differences of natural character. Every one 

 must feel the force of this remark. 



The circumstances by which man is surrounded in uncivilized 

 life, do not afford opportunities for the cultivation and enjoy- 

 naent of the higher faculties ; and, accordingly, we find that a 



