THE SKIN. 177 



3, What is dandruff? Is there any thing similar to it from the 

 surface of the whole body? 



4, What is the top layer of the skin called? What is the deep 

 layer of the skin called? What are the papillae, and where are 

 they situated ? 



5, What makes the ridges and furrows on the skin of the palm? 



6, What are the pores? Describe a sweat-duct. Describe a 

 sweat-gland. Where does the sweat come from? How does it get 

 into the duct? What is the estimated number of pores? What is 

 the estimated length of all the ducts combined? 



7, What is insensible perspiration? What is sensible perspira- 

 tion? 



8, What is the use of the hair? What does it grow from? How 

 do the muscular fibers of the skin act on the hairs? 



9, Where are the sebaceous glands, and what do they do? 



10, What is the use of the nails? What do they grow from? 

 What is the root of the nail? What is the matrix of the nail? 

 When a nail comes off, is it ever restored? When is it not restored? 



11, Name three uses of the skin. 



12, What is the natural heat of the inside of the body? 



13, How is it kept just at this temperature? 



14, What makes heat in the body? 



15, How is the temperature of the different parts kept equal? 



16, How do clothes keep the body warm? In what two ways are 

 we helped to resist the cold? 



17, Describe the first-named method in which the skin acts as a 

 cooling-apparatus. Describe the second-named method in which 

 the skin acts as a cooling-apparatus. How can men endure a tem- 

 perature of 200 F.? 



SECTION II. 1. What shows the importance of the action of 

 the skin? 



2-6. What three things are necessary in order to keep the skin 

 healthy? How does the skin become clogged and over-sensitive? 

 How may we become liable to colds? What is the harm, of too 

 thick clothing? What are the advantages of rubbing the skin? 



7-10, WTiat is the use of bathing? Why is cold-water bathing 

 invigorating? What is the best safeguard against colds? What 

 cautions are to be observed in bathing? 



