QUESTIONS. 347 



What is light ? How long are the rays of light in coming from the 

 sun to us. How much greater is its velocity than that of a cannon 

 ball ? What is meant by refraction ? How are rays of light affected, 

 in passing through the crystalline lens, and the different humors of the 

 eye ? What discovery was made by Kepler ? Upon what does clear- 

 ness of vision depend? Explain why a man at the bottom of a well 

 can see the stars at noon. State the reasoning of Buffon to explain 

 why there are two objects on the retina, and but one in the mind. 

 Give the view of Dr. Reid. How do we learn to judge of distances 

 and magnitude by the eye ? 



CHAPTER V. 



INFANCY. 



(P. 134.) What does the period of infancy embrace? What is said 

 of the infancy of the human species? in different states of society? 

 How does the management of children among savage and among civ- 

 ilized nations compare ? What is the treatment of infants among the 

 savages of North and South America? among the Laplanders? 

 among the Dutch ? Italians ? Turks ? What is said in regard to the 

 food proper for infants? What facts are stated respecting the mortality 

 of infants iff London ? in France ? 



(P. 137.) What does the author consider to be the great cause of the 

 diseases of children ? of the hardy constitution and vigorous health 

 of savages? What is said of the gradual development of the mental 

 and bodily powers ? At what age is Man considered in his prime ? 



What statements in regard to memory in early infancy ? What was 

 Haller's explanation ? What is essential to a good memory ? What is 

 the basis of sound mental discipline in education ? 



(P. 139.) What is said of the duration of infancy? in different 

 Quadrupeds ? in Birds ? in Fishes ? in Insects ? 



What general remark upon the infancy of animals? upon the 

 t.rength of the maternal tie ? 



CHAPTER VI. 



OF THE GROWTH AND FOOD OF ANIMALS. 



(P. 141.) What is the general process of nutrition ? Wi.at part of it 

 is yet a mystery ? Of what is the food of Man composed ? What is 



