190 PHYSIOLOGY AND HEALTH. 



is almost intolerable in August. We are sometimes nearly 

 overcome, at least languid, with the heat of a thawy day of 

 February, when the thermometer is no higher than 40. 

 But we are chilled with the air of the same temperature in 

 July. For this reason, we need to have our sitting-rooms 

 somewhat warmer in the summer than in the winter. An 

 ice-house is a sufficiently warm and comfortable place for a 

 man to work in while storing ice in the winter, but it is 

 chilly and often dangerous to those who enter it in the sum- 

 mer to take ice away. 



445. To demonstrate how much more rapidly the heat 

 passes away, and how much less power of resistance to cold 

 the animal body possesses, when it is under the influence 

 of its summer, than when under the winter constitution, 

 Dr. Edwards, of Paris, took several sparrows from their 

 warm rooms, in the month of February, and put them in a 

 cage surrounded by ice, where the temperature was, at the 

 highest, 32 ; after remaining there three hours, they had 

 cooled less than 2. He tried the same experiment in the 

 month of July, with the same conditions and in the same 

 time; the sparrows lost 21 of heat.* 



446. We gradually pass from the intensity of summer's 

 heat through the autumn to the severity of winter's cold, and 

 back again through the spring ; and as each of these oppo- 

 site seasons comes upon us, we receive the constitution 

 adapted to it, and endure the extremes of temperature with- 

 out suffering. But we cannot leap from the one to the 

 other with impunity. A resident of Massachusetts would be 

 enervated by suddenly arriving in the West Indies in the 

 winter ; and if, after residing under the equator for a season, 

 he should as suddenly return to Boston in January, he would 

 suffer from the cold. 



447. The dwellers in warm houses, and the workmen in 

 warm shops, retain the summer constitution through the 

 winter more than the out-of-door laborers, and cannot bear 



* Influence of Physical Agents on Life, Part III. Chap. III. 



