QUESTIONS FOBMING A COMPLETE INDEX. 



LESSON V. 



Animals, distribution of 132 



Arms and hands, why do we see 



blue marks upon them 89 



Arms and legs, why does it require 



the influence of the will to set 



them in motion 917 



Arms and legs, why are they made 



subject to the will 919 



Ascending, what is the cause of 



bodies 775 



Atmosphere, how is it heated ... 23:. 

 Atmospheric humidity, why does 



it sometimes form clouds, at 



others form dews, fogs, mists, &c. 409 

 Atmospheric pressure, how high 



will it raise water 65; 



Atmosphere, what is the 639 



Atmosphere, to what height does 



it extend 639 



Atmosphere, what is the amount 



of its pressure 641 



Atmosphere, what is the propor- 

 tion of watery vapour in the ... 642 

 Atmosphere, why are its upper 



regions intensely cold 441- 



Atmosphere, what is the greatest 



height ever reached in the ... 618 



LESSON VI. 



Atmospheric pressure, what is the 

 total amount on the earth's 

 surface 644 



Atmosphere, what is the amount 

 of its pressure upon t he human 

 body 645 



Atmosphere, why do we not feel 

 its pressure 646 



Atmosphere, to what extent may 

 its pressure vary 702 



Attractive agent, what is an ... 7<i 



Attraction, what is it 772 



Attraction, how many kinds are 

 there 773 



Aurora Borealis, what is the cause 

 of 590 



Bananas or plantains, where are 

 they cultivated 1220 



Bark Peruvian, where is it pro- 

 duced ... 122S 



Barometer, what is a ... ... 691 



Barometer, why does it indicate 

 the pressure of the atmos- 

 jhere 6D2 



Barometer, why is it also called a 

 "weather-glass" 693 



Barometers, why are they con- 

 structed with circular dials ... 694 



Barometer, why does the hand 

 change its position when the 

 mercury rises or falls 695 



Barometer, why does tapping its 

 face cause the hand to move ... 696 



Barometer, why does its fall de- 

 note the approach of rain ... 699 



LESSON VII. 



Barometer, why does its rise de- 

 note the approach of fine 



weather 700 



Barometer, how does it enable us 



to calculate ihe height of the 



mountains 701 



Barometer, when does it stand 



highest 704 



Barometer, when does it stand 



lowest 705 



Barometer, what effect has heat 



upon the TO" 7 



Barometer, what effect has cold 



upon the 708 



Balloons, why do they ascend in 



air 833 



Balloons, why do air balloons 



become inflated ' 831 



Balloons, why do they sometimes 



burst whtn they reach a high 



altitude 832 



Bat and ball, what principles of 



natural philosophy are illus- 



tra'ed in the play 867 



I'ats, why have they hooked 



claws in their wings 1079 



Bats, why do they fly by night ... 1080 



LESSON VIII. 



Hats, why do they sleep during 



winter 1081 



Beds, why should they be raised 



two feet from the ground ... 15 

 Bed-room windows, why are they 

 sometimes covered with ice 



crystals 3i4 



tieer, why will it not run out of 

 a cask until a hole is made at 



the top 660 



3eer, why d ws it get flat 805 



Jees, why have they stings ... lltl 

 Sees, why may we expect fine 

 weather when bees wander far 



from their hives 1114 



Jeetles, why are they called 



" coleoptera " 1319 



Jeotles, why have they hard horny 



wing-cases 1320 



Jeetles, why have many of them 



hard horns 1321 



Jile, why does it separate nutri- 

 tious from innutritions matter 881 

 >irds, why have water- fowls 

 feathers of a close and smooth 



texture 1033 



irds, why are they covered with 



feathers 1030 



irds, why does black down grow 

 under their feathers on the 



approach of winter 1036 



irds, why have they hard beaks 104U 

 iirds, why are their beaks 

 generally long and sharp ...1041 

 lirds, #hy are their bones hollow 1060 

 !irds, why do they 'ay eggs ... 1051 



