THE SENSES 145 



usually bring general sensations ; the spinal and cranial nerves usually 

 bring special sensations. 



Examples of general sensations are hunger, thirst, satiety, nausea, 

 faintness, giddiness, fatigue, weight, aching, shuddering, restlessness, 

 blues, creepy feeling, tingling, sleepiness, pain, illness. Any nerve can 

 convey the general sensation of pain, if injured along its course. If a 

 nerve of touch is cut, there is no sensation of touch, but of pain. Touch 

 sensations come only from the ends of the nerves. General sensations 

 are of many kinds. We are only half conscious of some of them ; many 

 of them are hard even to describe. 



Hygiene of the General Sensations. --General sensation is an invalu- 

 able aid to the health. Without it as a guide, the body could not 

 remain alive a single day. Pain should be heeded as our best friend, 

 and not killed with poisonous drugs as if it were our worst enemy. 

 We should not deaden the stomach ache with an after-dinner cigar. 

 If we do not go to bed when sleepy, the desire for sleep may leave us, 

 and we will undergo untold suffering from sleeplessness. Thirst should 

 be satisfied with cool water, which quenches it the best ; he who makes 

 his teeth ache with ice water will inflame his stomach and be continually 

 thirsty. He who does not stop eating when his hunger is satisfied, will 

 distend his stomach with food, and the stretched organ will be harder 

 to satisfy thereafter ; in fact, eating after a feeling of satiety may cause 

 indigestion so that the cells will not get the food. A dyspeptic is always 

 hungry, for the cells are starving. Fatigue of body or mind gives us 

 wise counsel ; but this feeling may be deadened by alcohol or tobacco, 

 and work continued until the body is injured. We should heed the 

 warning of pain or fatigue or restlessness as promptly as an engineer 

 heeds a red flag on the railway track. One who uses narcotics acts 

 like a reckless engineer who removes the danger signal and goes ahead, 

 hoping by good luck to escape an accident. 



Most of the nerves of touch end in papillae of the dermis 

 as microscopic, cgg-sJiapcd bodies (Fig. 120). There are 

 also many in the interior of the mouth, especially on the 

 tongue. On the palms they are arranged in curved lines, 

 and on the tips of the fingers they are in circular lines, 

 with one papilla in the center. The delicacy of the sense 

 of touch varies very much in different parts of the skin. 

 This delicacy refers to two tilings : the ability to feel the 

 slightest pressure and the ability to tell the exact point of 



