TOUCH, TEMPERATURE, MUSCULAR SENSE. 485 



in cold water for some time. If, now, both hands be 

 plunged into hike-warm water it will appear warm to one 

 hand and cold to the other. 



The ability to determine differences in temperature lies 

 within comparatively narrow limits. A reduction of a tem- 

 perature much below that of the body soon produces pain. 

 An elevation of a temperature much higher a corresponding 

 pain or burn. The finest distinctions in temperature are 

 made when these temperatures are about those of the body. 

 Different regions of the body show different abilities to per- 

 ceive changes in temperature. A few given in the order of 

 their ability, beginning with the best, are, the point of the 

 tongue, eyelids, cheeks, lips, neck. It is interesting to 

 note that the hands and feet seem to follow no regular rule 

 at all, but are warm or cold or insensitive under the most 

 varying conditions. Possibly this is the result of the ex- 

 posure which these parts surfer almost continually to the 

 ever-changing temperature of their environment and so be- 

 come somewhat dulled. 



The sense of temperature is very exactly localized. In 

 fact, changes in the temperature of two points may some- 

 times aid in their perception as two when otherwise they 

 would have been perceived as single. The general feel- 

 ing of cold and heat are not really sensations of the en- 

 tire body, but are simply extended skin sensations. The 

 body feels cold when the skin is cold, even though the 

 interior of the body may be warm. This, for instance, 

 is proved by the chills of many fevers, which chills are 

 usually accompanied with an actual increase of inner tem- 

 perature. On the other hand, the general feeling of warmth 

 which the toper experiences after his draught is really not 

 an increase of bodily heat at all, but is simply explained 

 by the fact that under the action of alcohol the blood 

 from the warmer visceral organs is driven through the skin. 

 As an actual fact from the radiation of the heat going on 

 in the skin his bodily heat is actually being more rapidly 

 reduced. 



