SCIENTIFIC READINGS. 



131 



416. What may be the result of the combination of 

 oxygen with a combustible body ? 



417. What is the product of the combination of oxygen 

 with a metal ? 



418. What would be the consequence if the oxygen 

 were abstracted from the atmosphere ? 



419. Is there any exception to the general poisonous 

 nature of the oxides of metals ? 



4 C 20. How may oxygen be obtained for experiment ? 



421. What is the meaning of the word oxygen ? 



422. Does oxygen ever exist in a solid state r 



423. Why does not the atmosphere become so dete- 

 riorated through a constant loss of oxygen, as to be in- 

 capable of supporting respiration ? 



424. What is the other principal constituent of the 

 atmosphere ? 



425. Does Nitrogen ever exist in a solid state, and to 

 what is it indebted for its fluidity 1 



426. What are the properties of Azote or Nitrogen ? 



427. How may nitrogen be obtained ? 



428. Does nitrogen combine with any other body ? 



429. What does the combination of nitrogen and hy- 

 drogen produce ? 



430. What other gas besides oxygen and nitrogen 

 enters into the composition of atmospheric air ? 



431. Required the properties of Carbonic acid gas. 



432. What is the name that miners give to carbonic 

 acid gas ? 



433. Describe the Grotto del Cano. 



434. What domestic operations produce carbonic acid 

 gas? 



435. To what do Champagne and bottled Cider owe 

 their sparkling qualities ? 



436. Of what use is Carbonic acid gas in vegetation? 



437. Which gas has the greatest specific gravity? 



438. How may carbonic acid gas be procured? 



439. Required the process of making lime. 



440. What substance is peculiarly noted for its anti- 

 septive properties ? 



441. What gas do animal and vegetable substances 

 give out when in a state of putrefaction ? 



