IN HYGIENIC PHYSIOLOGY. 161 



The volume or loudn&ss of the voice depends mainly on the 

 combination of quantity of air with greater force of expulsion. 

 Loudness, with clearness, also demands a peculiar resonance 

 up in the nasal cavities and sinuses. Lastly, the unnatural or 

 falsetto voice seems also to be produced by some tensive change 

 effected in the upper part of the pharynx at the back of the 

 nose : hence it is called by singers the head voice, in contradis- 

 tinction to the ordinary, or chest voice. MARSHALL. 



2. Why can ive see our breath on a frosty morning ? 



The vapor of the breath is condensed by the cold air. 



3. When a laiv of health and a laiv of fashion conflict , 

 which should ^ve obey ? 



It depends, of course, whether we prefer to be fashionable 

 or to be healthy, to obey man or God. With too many people 

 the former is of far greater importance, and in selecting an 

 article of dress, few ask or think about the latter. The conse- 

 quence is seen in the weakened frame, the prevalence of dis- 

 ease, and the shortened life. God's laws written in our bodies 

 can not be violated with impunity. 



4. If we use a " bunk " bed 9 sJioidd we pack away the 

 clothes when ive first rise in the morning ? 



No. They should first be thoroughly aired. 



5. Why should a clothes-press be ivcll ventilated? 



The clothes naturally contain the products of the insensible 

 perspiration, which passing off, pollute the air of the closet. 



6. Sliould the weight of our clothing Jiang from the 

 tvalst or the shoulder ? 



From the shoulder, so as to avoid the constriction of the 

 compressible organs in the abdomen. 



7. Describe the effects of living in an overheated 

 room. 



(1) The body becomes moro sensitive to change, and the 

 susceptibility to colds is greatly increased ; (2) the dry, heated 

 air abstracts the moisture from the skin, rendering it dry, hard, 

 and incapable of performing its normal functions. 



