XVI 



QUESTIONS FORMING A COMPLKTK INHKX. 



LESSON XXXVII. 



Heat, is water a good or a bad 

 conductor 151 



Heat, how do we know that air is 

 not a good conductor ... ... 155 



Heat, how do we know that water 

 is not n good conductor 156 



Heat, why ore bottles of hot water 

 wrapped in flannel ... ... 158 



Heat, why are hot rolls wrapped in 

 flannel 159 



Heat, what is the highest degree 

 that man can bear ... ... ... 176 



Heat, why may man endure a high 

 degree without injury 178 



Heat, why may we believe that 

 the internal heat of the earth 

 does not arise from terrestrious 

 combustion 224 



Heat, what is the radiation of ... 181 



Heat, what becomes of that which 

 is radiated ... 186 



Heat, when does a body radiate it 184 



Heat, does the movement of the air 

 aff-ct the radiation of 188 



Heat, why will not the motion of 

 air disturb the rays of 190 



Heat, what bodies are good radia- 

 tors ot 192 



Kent, what bodies are bad radia- 

 tors of 193 



H.'at, why does water keep hot 

 longer in a bright metal jug ... 195 



LESSON XXXVIII. 



Heat, may it bo reflected 210 



Heat, are light or dark-coloured 



bodies the best reflectors ... 211 

 Heat, what bodies are the best re- 

 flectors of" 212 



Heat, why is that which is reflected 



less intense than the primary ... 214 

 Heat, can it be reflected in any 



great intensity 215 



Heat, are good reflectors also good 



absorbers ' 216 



Heat of the sun's rays, how is it 



diffused 219 



Heat, how do we know that it U 



absorbed by the earth 222 



Heat, do plants absorb it ... ... 225 



Heat, how is it diffused through 



the atmosphere 232 



Heat, how is it diffused through the 



ocean ... 233 



Heat, why is it developed during 



chemical changes 312 



Heat, what are the sources of ... 323 

 Heat, what is the accepted theory 



of 328 



Heat, what is the point at which 



it becomes luminous 545 



Heat, what is the relative intensity 



of primary and reflected ... 548 



Hent to cold, why does a sudden 



change bring on illness 1013 



LESSON XXXIX. 



Heat of the earth, HumbolJt'a 

 opinion upon the int rual ... 1335 



Heat of the earth, Hunt's opinion 

 upon the internal ]3.'?6 



Hfar, why do we P83 



Hiccough", why do we 1027 



Hoar-frost, what is it 362 



Hoar-frost, why does it foretell 

 rain 363 



Hoar-frosts, why are they so fre- 

 quent, and black-frost so unfre- 

 quent ... 412 



Hogs, why have Indian large tusks 

 turning back towards their eyes 1068 



Hog, why is the under-jaw of the, 

 shorter than the upper-jaw ... 1039 



Hoop, why does it roll without fall- 

 ing to the ground 861 



Hoop, why does it when falling 

 make sevend side revolutions ... 862 



Horses, why ha-'e they smaller 

 stomachs proportionately than 

 other animals 1097 



Horse, why has it no gall-bladder 1098 



Hordes, why is the secretion of 

 : their eyes thick and flutinous ... 1134 



Horses and cattle, why do they 

 stretcfc out their neckc, and snuff 

 the ir on the approach of rain ... HOC 



Horse-chestnut, why is it unfit for 

 f"od 1203 



Hot, when is a body said to be ... 77 



LESSON XL. 



Hot water, why does it feel hotter 

 in a metal jug than in an earthen- 

 ware one ... ... ... ... 126 



Hot metal, why does it feel hotter 

 than hot wool 130 



Hot metal and hot wool, which 

 would become cold first 131 



Hot and cold bodies, why, when 

 placed near each other, do their 

 temperatures approximate ... 331 



Humming-tops, why do we see the 

 figures painted on them before 

 they spin, but not while they are 

 spinning 813 



Humming-top, why does it make a 

 noise gio 



Hydrogen, what is it 49 



Hydrogen, will it support animal 

 life 50 



Hydrogen, will it support combus- 

 tion 51 



Hydrogen, why will it explode ... 52 



Hydrogen, where does it chiefly 

 exist 54 



Hydrogen, how is it obtained from 

 coal 57 



Hydrogen-gas, is an escape of ic 

 dangerous to life 63 



Hydrogen-gas, 'what proportion 

 mixed with air will explode ... 64 



Hydrog- "-gas, doe* it rise or fall " 6t> 



