CHEMICAL PARADOXES. 



nearly always present in combustibles our 

 flames practically always produce water. 



The reason why it is not more commonly ob- 

 served is that hot air and gas can hold a greater 

 quantity of water-vapour in solution than cold 

 gases can ; so that the excess of water- vapour, 

 though present in the flame, is not often easily 

 seen. 



2. Water a Source of Fire. 



That water, which is commonly used for 

 putting out fires, should be capable of causing 

 and maintaining them, sounds sufficiently para- 

 doxical. It is, nevertheless, perfectly and liter- 

 ally true. 



Water consists of two parts of hydrogen gas 

 combined with one part of oxygen. Oxygen 

 is an element which has a very strong tendency 

 to combine with sodium and potassium, so 

 strong that if either of these metals is thrown 

 upon water, in combining energetically with the 

 oxygen it tears it away violently from part of 

 the hydrogen with which it is already combined 

 in the water, setting this portion of hydrogen 

 free. 



We all know how two bodies coming 

 violently together develop heat as. the result of the 

 impact. Without further reference to the moral 

 (or immoral) heat developed when two persons 

 collide, owing, as each thinks, to the stupidity 

 of the other, there is much physical heat 



204 



