226 MENTAL AND PHYSICAL EXERCISE. 



ward, or alternately in all these directions, the straight- 

 muscles (Fig. 104), are thrown into alternate contrac- 

 tion and relaxation, at the mandate of the brain. Mean*- 

 time the visual portion of the eye furnishes us with a 

 picture of the landscape, the different parts of which 

 we thus examine, by means of the mechanical portion. 

 Is it not plain that infinite wisdom and Almighty power 

 only, could have devised and constructed such machinery 

 as this ? 



708. Personal Temperament and Disposition accounted 

 for. It is on the same principles that we can account for 

 the difference which we observe in persons with respect 

 to their temperaments or dispositions, as already stated. 

 When we see a person of feeble muscular pow r ers easily 

 thrown into agitation, turning pale, or fainting by slight 

 causes, and morbidly sensitive to every nervous impres- 

 sion, we may conclude that in such persons the sentient- 

 nervous system predominates ; or, in other terms, that 

 the nerves which carry impressions to the brain, are 

 either more highly developed, or are in a more sensitive 

 state than those concerned in muscular contraction. In 

 such persons, the flesh is commonly soft to the touch, 

 and has a pallid hue. On the contrary, in persons where 

 there is great muscular power, as indicated, not only 

 by the strong outlines of the muscles themselves, but 

 also by the capability of enduring great and continued 

 bodily exertions, and by a temperament void of excessive 

 sensibility, being able to bear strong nervous impressions 

 with little indication of nervous feeling; we may con- 

 clude that in such persons the motor-nerves, or those 

 concerned in muscular contraction, predominate over 

 those subservient to sensation. In such persons, the 

 muscles are commonly rigid to the touch, even when 

 relaxed, presenting a striking contrast with the morbid 

 softness of those parts, in persons of excessive nervous 

 mobility. 



709. Natural Disposition may be modified. Although, 

 as we have supposed, and the fact cannot be doubted, that 

 there is a natural difference in different persons, with 

 respect to the distribution of the sentient and muscular 



