IN HYG1UXIC PHYSIOLOGY. 191 



33. State the close relation which exists between phys- 

 ical and mental health and disease. 



A partial cultivation of the mental faculties is incompatible 

 not only with the highest order of thought, but with the high- 

 est degree of health and efficiency. The result of professional 

 experience fairly warrants the statement that in persons of a 

 high grade of intellectual endowment and cultivation, other 

 things being equal, the force of moral shocks is more easily 

 broken, tedious and harassing exercise of particular powers 

 more safely borne, than in those of an opposite description, 

 and disease, when it comes, i3 more readily controlled and 

 cured. The kind of management which consists in awakening 

 a new order of emotion, in exciting new trains of thought, in 

 turning attention to some new matter of study or speculation, 

 must be far less efficacious, because less applicable, in one 

 whose mind has always had a limited range than in one of 

 larger resources and capacities. In endeavoring to restore the 

 disordered mind of the clod-hopper who has scarcely an idea 

 beyond that of his manual employment, the great difficulty is 

 to find some available point from which conservative influences 

 may be projected. He dislikes reading, he never learned amuse- 

 ments, he feels no interest in the affairs of the world ; and, 

 unless the circumstances allow of some kind of bodily labor, 

 his mind must remain in a state of solitary isolation, brooding 

 over its morbid fancies, and utterly incompetent to initiate any 

 recuperative movement. Dr. RAY. 



34. In ivhat consists the value of the power of habit? 

 It saves the "wear and tear" of our principles. We can 



perform an act a few times, though with difficulty, and then 

 ever after it becomes a habit. "We resist evil once, and thence- 

 forth it is easier to resist. We can become accustomed to do 

 good, so that the chances will all be in favor of our well-being 

 in any emergency. By so much as the power of habit is thus 

 pregnant with good, by so much is it susceptible of terrible 

 evil. 



35. How many pairs of nerves supply the eye ? 



(See Physiology, p. 199.) 

 Three ; the motores oculi. 



