234 THE BRAIN. 



clothing of different kinds, and of living upon all 

 kinds of food, that enables man to dwell in every 

 part of the world. 



Questions. 



In what place are the organs of voice situated ? 



What produces sound ? 



How are different tones produced? 



What parts modulate the sound, and enable us to speak 1 ? 



Have other animals voice 1 



Is the voice of animals more limited than our own 7 



What happens to the voice when we labour under a cold ? 



How does our body differ from vegetables and minerals as 

 to warmth ? 



Does the heat of our body vary much under different 

 temperatures ? 



About what degree of the thermometer is it found ? 



What advantages do we derive from this equal temperature 

 in all situations ? 



LESSON XIII. 



THE BRAIN THE SPINAL MARROW ORIGIN OP 



NERVES SUPERIORITY OF MAN. 



ALMIGHTY GOD, in making our bodies, has care- 

 fully protected those parts which are most impor- 

 tant to our well being. Thus the heart and the 

 lungs are covered and shielded by the ribs, breast- 

 bone, and spine ; and the stomach is placed amidst 

 soft and yielding parts, that it may give way to 

 blows or fulness. It is, however, in those organs 



