413 



PART V. 



SKIN. 



CHAPTER I. 



448. What protects the organs of life from external agencies I 



449. Describe the cuticle. 450. Is it subject to change 1 



451. When does it become thick and tough? 



452. Will every kind of friction produce this effect? 



453. What is the effect of friction gradually applied ? 



454. To what extent may the outer skin be made thick and tough f 



455. How does new and coarse work affect the hands ? 



456. How are corns produced ? 



CHAPTER II. 



457. What protection does the cuticle afford ? 



458. What other parts grow out of the cuticle? 



459. Describe the nail. 



4GO. What is the structure of the hair ? 



461. How is the scarf-skin kept fresh and new ? 



462. Where is the seat of color? What is the rete mucosum? 



463. What produces various hues in some animals ? 



464. Describe the true skin ? 



465. When is the surface florid? What may make it more sof 

 Less so ? 



466. What sense and what degree of sensibility are in the skin ? 



467. What is directly under the skin ? Where thick ? Where thin t 



CHAPTER III. 



468. In what form does the waste of the body escape through the 

 skin? In what quantity? What was Sanetorius's experiment? 



469. At what results did Seguin arrive ? 



470. How can this insensible perspiration be made manifest? 



471. What is sensible perspiration? Which is constant? Which 

 greatest in the whole amount ? 



472. 473, 474. Relate the experiments at the Phoenix gas works. 



475. How is the weight of the body kept uniform? 



476. What is the average amount of cutaneous exhalations ? What 

 produce variations? 



CHAPTER IV. 



477. What external circumstances modify the amount of perspira- 

 tion ? 



478. What is the effect of the atmosphere saturated with moisture t 



479. Describe the minute structure of the perspiratory organs. 



35* 



