48 THE EEASON WHY. 



"Wisdom is the principal thing; therefore get wisdom: and with all thy 

 getting get understanding." PROVEEBS iv. 



129. Will a kettle-holder, being a lad conductor, sometimes 

 conduct heat to the hand ? 



Yes. But so slowly that the hand will noifeel the inconvenience 

 of too much heat. 



130. Why does hot metal feel hotter than heated wool, 

 though they may both be of the same degree of temperature ? 



Because metal gives out heat more rapidly than wool, by 

 which it is made more perceptible to our feelings. 



131. Which would become cold first the metal or the 

 wool ? 



The wool, because, although the metal conducts heat more 

 rapidly, to a substance in contact with it, it does not radiate heat 

 as well as a black and rough substance. 



132. Why do iron articles feel intensely cold in winter ? 

 Because iron is one of the best conductors, and draws off heat 



from the hand very rapidly. 



133. What is the cause of the sensation called cold ? 

 When we feel cold, heat is being drawn off from our bodies. 



134. What is the cause of the sensation called heat ? 

 When we feel hot, our bodies are absorbing heat from external 



causes. 



[The condition here implied is that of health, and of ordinary circumstances. 

 A person in a condition of fever, suffering from intense heat arising from a 

 diseased state of the blood, could not be said to be absorbing heat. Nor could 

 such a description apply to a person who, by a very rapid walk, has raised the 

 temperature of his body considerably above its natural state, by the internal 

 combustion which has already been described. A person feeling hot in bed, 

 from excessive clothes, feels hot from the development of Jieat internally, which 

 is not conducted away with sufficient rapidity to maintain the natural tempe- 

 rature of the body.] 



135. If a person, sitting before afire-place, without afire, 

 were to set one foot upon a rug, and the other upon the stone 

 hearth, which would feel the colder ? 



The foot on the stone, because stone is a good conductor, anil 

 would conduct the warmth of the foot away from it. 



