IV. 



THE TOUCH A FALSE WITNESS, 

 i. The Hotter feeling the Colder. 



NOT only are heat and cold relative things, 

 greater cold meaning simply a state in which 

 there is less heat ; but our perceptions of heat 

 and cold are relative also. A thing is felt to 

 be hot or cold in relation to the temperature of 

 our body or part of our body ; and not merely 

 in relation to the natural heat of the blood, a 

 little over 98 F., but in relation to the previ- 

 ous temperature of the hand or other part, 

 which may itself have been heated or cooled by 

 contact, with air, water, or other substances. 

 A well-known instance makes this principle 

 very clear. 



Take three large jugs of water, one as warm 

 as it can be without discomfort to a hand which 

 remains in it for some time, one cold, and the 

 third obtained by mixing equal parts of the 

 two preceding, so that its temperature will be 

 intermediate. Fill the basin A (Fig. 58) from 

 the jug of warm water, B from that of cold, and 

 C and D with the water of intermediate 

 temperature. 



Let some person who has not seen these 

 259 



