196 Life and Health 



to the temporary loss of heat at the surface, a freer play of 

 the general vital powers. 



297. Hot Baths. Hot baths should be taken at night 

 before going to bed, as in the morning there is usually 

 more risk of taking cold. The body is readily chilled if 

 exposed to cold when the blood vessels of the skin have 

 been relaxed by heat. Besides their use for the purposes 

 of cleanliness, hot baths have a sedative influence upon the 

 nervous system, tending to allay restlessness and weariness. 

 They are excellent after severe physical or mental work 

 and give a feeling of restful comfort like that of sleep. 



Experiment 87. To illustrate the sense of temperature. Ask the 

 person to close his eyes. Use two test tubes, one filled with cold and 

 the other with hot water, or two spoons, one hot and one cold. Apply 

 each to different parts of the surface and ask the person whether the 

 touching body is hot or cold. Test roughly the sensibility of different 

 parts of the body with cold and warm metallic-pointed rods. 



Experiment 88. Touch fur, wood, and metal. The metal feels 

 coldest, although all the objects are at the same temperature. Why ? 



Experiment 89. Plunge the hand into water at about 97 Fahr. ; 

 one experiences a feeling of heat. Then plunge it into water at 

 about 86 Fahr. ; at first it feels cold, because heat is abstracted from 

 the hand. Plunge the other hand directly into water at 86 Fahr. 

 without previously placing it in water at 97 Fahr. ; it will feel 

 pleasantly warm. 



Experiment 90. To illustrate warm and cold spots. With a 

 blunt metallic point, touch different parts of the skin. Certain 

 parts feel a sensation of warmth, others of cold, although the tem- 

 peratures of the skin and of the instrument remain constant. 



^ 298. Cold Baths. Cold baths serve as an excellent tonic 

 and stimulant to the bodily functions. The best time for 

 a robust person to take a cold bath is in the morning, 

 immediately after rising. 



