240 SCIENCE OF COMMON THINGS. 



Activity disagreeable in warm weather. 



tible ; and as these people live in climates of intense 

 cold, the heat of their bodies is increased by the greasy 

 nature of their food. 



1610 Why do we feel lazy and averse to activity in very hot weather 1 



Because muscular activity inweases the heat of our 

 body by quickening respiration, and lessens our desire 

 for active exertion. 



1611 How much more carbon do we throw off from the system by respi- 

 ration in winter than in summer f 



Full one-eighth more. 



