THE SKIN 245 



fluence allowing the vessels to expand. More blood now 

 flows through the skin, it becomes flushed and warm, and 

 there is a feeling of exhilaration in the body. This " after- 

 glow " may last a long time, and the person should leave the 

 water while still under its influence. If he stays in longer, 

 the blood vessels may again contract, making him chilly, 

 and since this time there is no subsequent reaction to warm 

 the body, he is likely to be cold and uncomfortable for many 

 hours. The length of time that the after-glow may continue 

 depends upon the person, the temperature of the water and 

 to a certain extent upon its character, lasting longer if the 

 water is salt, than if fresh. 



The after-glow from a cold bath is increased if it is accom- 

 panied by a vigorous friction of the skin. Energetic rubbing 

 with a rough towel is of as much value as the bath as a stimu- 

 lant for the skin, and without it the bath accomplishes only 

 half its purpose. Rubbing with towels pulls to a slight degree 

 on every part of the surface, stretches the different tissues in 

 the dermis, dislodges any loose epidermis, and leaves the skin 

 alert and ready to perform its duties. In short, the cold 

 bath and the " rub " are to the skin what the gymnasium is 

 to the skeletal muscles. 



Since one of the chief objects of the cold bath is to shock 

 the skin, there is no reason why one should not take a plunge 

 into cold water, even when hot and sweaty, provided he 

 does not stay in long enough to become chilled. The shock 

 is an advantage, the cooling is refreshing. On the other hand 

 to take a cold plunge when one is already cold is neither 

 pleasant nor profitable, unless it is followed at once by a 

 vigorous friction which develops the proper after-glow. Cold 

 baths should always be taken when one is warm, e.g. when 

 just out of bed or after vigorous exercise. After a night's 

 rest in a horizontal position, the heart is beating slowly, blood 

 is flowing sluggishly and nerves are stupid. A cold bath at 

 I such a time is the best stimulant a person can take to get 



