THE EEASON WHY. 35 



As coals are to burning coals, and wood to fire ; so is a contentious man to 

 kindle strife." PKOVERBS xxvi. 



will extinguish a flame immersed in it. It is therefore said to bo 

 a body which will burn, but will not support combustion. 



46. What becomes of the nitrogen that is inhaled with the 

 air ? 



It is thrown off with the breath, mixed with carbonic acid gas, 

 and flies away to be renewed by a fresh supply of oxygen. 



47. Where does nitrogen find afresh supply of oxygen ? 

 In the atmosphere. Nitrogen is said to possess a remarkable 



tendency to mix with oxygen, without having a positive chemical 

 affinity for it. That is to say, neither the oxygen nor the nitrogen 

 undergoes any change by the union, except that of admixture. The 

 oxygen and the nitrogen still possess their own peculiar properties. 

 Oxygen and nitrogen are found in nearly the same proportions in all 

 climates, and at all altitudes. 



48. In combustion does any other result take place besides 

 the union of oxygen and carbon forming carbonic acid gas? 



Yes. Usually hydrogen is present, which in burning unites with 

 oxygen, and forms water. 



CHAPTER IV. 



49. What is hydrogen ? 



Hydrogen is an elementary gas, and is the lightest of all known 

 bodies. 



50. Will hydrogen support animal life ? 



It will not. It proves speedily fatal to animals. 



51. Will hydrogen support combustion ? 



Although it will burn, yielding a feeble bluish light, it will, if pure, 

 extinguish a flame that may be immersed in it. Hydrogen will 

 therefore burn, but will not support combustion. 



52. Why will hydrogen explode, if it will not support com- 

 bustion ? 



When hydrogen explodes it is always in combination with oxygen, 



