THE SPECIAL SENSES. 181 



powers ; indicates the approach of disease ; and calls at- 

 tention to it when present. The word disease, in fact, 

 according to its original use, had reference simply to the 

 pain, or want of ease, which commonly attends disordered 

 health. When we observe the serious mishaps which occur 

 when sensibility and pain are absent, we cannot fail to 

 appreciate its value. For example, a paralytic in taking a 

 foot-bath, forgets to test its temperature, and putting his 

 limbs into water while it is too hot, is severely scalded 

 without knowing it. 



11. A traveller, overcome by cold and fatigue, lies down 

 and falls asleep near a large fire, and when he is aroused in 

 the morning, it is discovered that one of his feet has been 

 insensibly destroyed. A grain of sand, lodging in an insen- 

 sitive eye, may cause inflammation and even the loss of 

 sight. If intense light were not painful to the eye, many 

 a child would innocently gaze upon the glories of the sun 

 to the ruin of his sight. 



12. Pain is, indeed, a present evil, but its relations with 

 the future prove its mission merciful. Painful impressions 

 cannot be recollected from past experience ; and they can- 

 not be called into existence by the fancy. Considered in 

 the light of results, pain has a use above that of pleasure ; 

 for while the immoderate pursuit of the latter leads to 

 harm, the tendency of pain is to restrict the hurtful courses 

 of life, and in this manner to protect the body. 



13. The relations of pain to pleasure are thus described 

 by the eminent physiologist, Magendie: "By these sensa- 

 tions Nature induces us to concur in the order which she 

 has established among organized beings. Though it may 

 appear like sophistry to say that pain is the shadow of 

 pleasure, yet it is certain that those who' have exhausted 

 the ordinary sources of pleasure have recourse to the 



1 1 . The case of the traveller ? Grain of sand ? The <?nn and child ? 



1 2. Mission of pain ? Painful impressions compared with those of pleasure ? 



13. What does Magendie say of the relation of pain to pleasure ? 



