l6o ANSWERS TO PRACTICAL QUESTIONS 



This depends entirely on circumstances the amount 

 of exercise, freedom and character of perspiration, state 

 of the system, etc. Each case must be decided by it- 

 self. 



36. Is abundant perspiration injurious ? 



No. It removes impure matter from the system, and 

 hence may be beneficial. It may, however, weaken the 

 body, and frequent hot baths should therefore be taken 

 only on suitable medical advice. 



99. i. What is the philosophy of the "change of voice" 

 in a boy ? 



Up to the age of fourteen or fifteen, there is little or 

 no difference in point of size between the larynx of a 

 boy and that of a girl; but subsequently the former 

 grows proportionately larger, so that at last, in the adult 

 male, the vibrating parts or vocal cords are necessarily 

 longer than in the female. They are also undoubtedly 

 thicker, perhaps even coarser in structure. From all these 

 circumstances the adult male voice is stronger, louder, and 

 of lower pitch than the weaker and higher vocal range 

 accomplished by the female larynx. 



The cause of the difference in quality of the voice, 

 known as its timbre, is not well known ; but it must 

 undoubtedly be dependent on physical, that is to say, 

 structural peculiarities in some part of the laryngeal 

 apparatus. 



The production of the different notes within the com- 

 pass of any one individual depends upon alterations in 

 the length and state of tension of the vocal cords, and on 

 their degree of proximity or separation from one another 



