THE SKIN 277 



into the scalp and later of removing this with a cleansing 

 shampoo. The olive oil is placed on the scalp with a medi- 

 cine dropper and thoroughly rubbed in with the fingers. 

 After three or four hours the hair is washed with soap 

 and water (any good toilet soap will do) and rinsed with 

 pure water. The hair is then dried, the surplus water being 

 removed with a coarse towel. Where the dandruff is very 

 troublesome, this treatment may be given once or twice a 

 week ; but in mild cases once a month is sufficient. Massage 

 of the scalp, by increasing the circulation at the hair roots, is 

 beneficial, but irritation by a fine-tooth comb, a stiff hair 

 brush, or by other means should be avoided. Frequent 

 brushing and combing, however, are necessary both for 

 the good appearance of the hair and for spreading the oil 

 secreted by the glands at the hair roots. 



Summary. The skin forms the external covering of 

 the body and also serves additional purposes. It is a most 

 important agency in adapting the body to its physical sur- 

 roundings, as shown by the part which it plays in the regu- 

 lation of the body temperature. The skin should be kept 

 clean and active, and skin wounds, even though small, 

 should be guarded against infection. 



Exercises. i. Name an example of each of the protective coverings 

 of the body. 



2. Compare the dermis and the epidermis with reference to thick- 

 ness, composition, and function. 



3. To what is the color of the skin due ? How is the color of the 

 skin affected by the sunlight ? 



4. What modifications of the epidermis are found on our bodies ? 

 What are found on the body of a chicken ? 



5. What different kinds of protection are provided by the skin ? 



6. How does the perspiration cool the body ? 



7. What change occurs in the circulation in the skin when the body 

 is becoming too cold ? When becoming too warm ? What is the pur- 

 pose of these changes ? 



