72 ANIMAL PHYSIOLOGY. [LESSON 24. 



FIG. 109. 398. The Epidermis consists of several layers, pro- 



duced by and forming the external surface of the cuti- 

 cle ; the external one being a series of horny, trans- 

 parent, flattened, scale-like cells (Fig. 109), the lower 

 layers of this tissue possess the true cellular character. 

 Scales of human The outer layers are continually being exfoliated, or 

 thrown off, and are as constantly being reproduced 

 below. The preservation of a healthy skin demands the removal of 

 the entire epidermic layer, by frequent ablution, always accompanied 

 by the liberal use of that valuable detergent soap. 



399. For the strict purposes of health, neither a plunge nor 

 shower bath is necessary the latter is even obnoxious to some tem- 

 peraments : the most comfortable and healthful form of bath is at 

 the same time the most facile a sponge bath expedition in its use 

 being the most important element. 



The bath itself should never exceed five minutes ; the rubbing 

 dry (the most essential part of the process) occupying another five 

 minutes or more an amount of time that every one can afford at the 

 beginning of the day. This bath should be taken immediately on 

 rising in the morning, as at such time reaction is greater and quicker 

 than at any other period of the twenty-four hours. 



It is very necessary to attend to the temperature of the water, 

 and of the room in which the bath is taken. During hot summer 

 weather, water may be used at the ordinary temperature of the at- 

 mosphere, the room indicating not less than 70 Fahrenheit. But at a 

 less external heat than 70 the water should be warm, or at least tepid. 



400- A sudden cold chill on the surface of the body is prejudicial 

 to health ; it checks the circulation of the blood to the external sur- 

 face, interferes with the secretions, and particularly arrests the excre- 

 ting power of the skin. 



401. It is a popular belief with mothers, that washing young 

 children daily, in cold water, makes them hardy. This is a grave 

 mistake ; the feeble circulation of a child requires the aid and assist- 

 ance of warmth warm water and warm clothing. The greatest 

 medical man who ever lived John Hunter recommended three 

 rules for the management of children, and they express the substance 

 of a volume ; he says, " give them plenty of milk, plenty of sleep, 

 and plenty of flannel." 



402. In this changeable climate, children and females are too 

 thinly clad, and the great mortality amongst females is mainly due to 

 this cause ; they are so much exposed to external influences that they 



