WATER. 171 



quickly into our foot, it raises its tempe- 

 rature so suddenly, that we cannot help 

 perceiving the increase of heat. 



Q. Why does the non-conducting power of the 

 HEAKTH-BUG prevent its feeling so HOT as it really 

 is ? 



A. Because it parts with its heat so 

 slowly and gradually, that we scarcely 

 perceive its transmission into our feet. 



Q. When we plunge our HANDS into a basin of 

 WATER, why does it produce a sensation of COLD ? 



A. Though the water (in which we 

 wash) is really warmer than the air of 

 our bed-room ; yet because it is a better 

 conductor, it feels colder. 



Q. Why does the CONDUCTING power of water 

 make it feel COLDER than the air, though in reality 

 it is WARMER ? 



A. Because it abstracts heat from our 

 hands so rapidly, that we feel its loss; 

 but the air abstracts heat so very slowly, 

 that its gradual loss is hardly perceptible. 



Q. Is water a GOOD CONDUCTOR of heat ? 



A. No; wo liquid is a good conductor 

 of heat ; but yet water is a much better 

 conductor than air. 



Q 2 



