PART IL 



PARADOXES OF PHYSICAL STATE. 



I. 



CURIOSITIES OF FREEZING AND MELTING. 



i. Ice melting while growing colder. 



SKATERS know how quickly ice will melt 

 away when the wind changes and a warm air 

 comes blowing over it. Travellers in Arctic 

 regions often have to obtain water for drinking 

 by putting ice into a pan over a fire. These 

 methods illustrate the melting of ice by apply- 

 ing heat to it ; but it is possible to melt it 

 without the application of heat while, on the 

 contrary, it is becoming colder. How is it 

 possible to melt ice without heat ? Well, the 

 fact is that it is not melted without heat, though 

 without the application of heat from external 

 sources. Heat is necessary to melt it ; but it 

 is contrived that it shall be the ice itself which 

 supplies the heat for its own melting 



For ice can supply it. Although ice is cold, 

 it is not on that account without heat. The 

 statement that it is cold only means that it has 

 less heat than our bodies, not that it has no 

 heat at all. All things with which we are 



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