THE SKIN. 191 



cold as well as they do without suffering, and therefore need 

 more clothing when exposed to the same temperature. A 

 shoemaker or student, going from his warm shop or room 

 and taking the outside seat of the stage-coach, by the side of 

 the driver, in winter, must wear thicker garments than his 

 companion who is daily exposed to the weather ; if he does 

 not do so, he will suffer more than the coachman. Those 

 who live in houses heated by furnaces, in which all the 

 entries and rooms are more or less warmed, and who seldom 

 go abroad, hardly receive the winter constitution in the 

 proper season, and cannot bear exposure to the open air 

 without much additional clothing. 



PART V. 



THE SKIN. 



CHAPTER I. 



The internal Structure needs Protection Skin. Cuticle; thick 

 ened by Friction if gradually applied. Blisters. Corns. 



448. THE inner framework and vital machinery of ani- 

 mals their lungs, heart, and blood-vessels their muscles, 

 nerves, and digestive apparatus are all very delicate, and 

 would ill bear exposure to the action of the elements, or even 

 the contact with other bodies. They are, there fore, protected 

 with some outward covering, which is different in different 

 animals. Yet, in all, it stands between these organs of life 

 and the external world. In man, and in many other animals, 

 this outward covering is the skin, which is a soft and pliable, 

 and yet a strong membrane, that is not easily injured or torn, 

 does not suffer from contact with other substances, and will 

 bear wide variations of heat and cold. 



