TEMPERATURE OF THE BODY. 233 



of new-born children is well known ; the researches of M. 

 Edwards show, that the want of it is, as Hunter suggested, 

 a much more frequent cause of death in new-born children 

 than is generally supposed, and furnish a strong argument 

 against the idea, that children, by early exposure to cold, 

 can soon be hardened into resisting its injurious influence. 



S eXf The average temperature of the female would 

 appear from observations by Dr. Ogle to be very slightly 

 higher than that of the male. 



Period of the Day. The temperature undergoes a gradual 

 alteration, to the extent of about I? to i J- F. in the course 

 of the day and night ; the minimum being at night or in 

 the early morning, the maximum late in the afternoon. 



Exercise. Active exercise raises the temperature of the 

 body. This may be partly ascribed to the fact, that every 

 muscular contraction is attended by the development of one 

 or two degrees of heat in the acting muscle ; and that the 

 heat is increased according to the number and rapidity of 

 these contractions, and is quickly diffused by the blood 

 circulating from the heated muscles. Possibly, also, some 

 heat may be generated in the various movements, stretch- 

 ings, and recoilings of the other tissues, as the arteries, 

 whose elastic walls, alternately dilated and contracted, may 

 give out some heat, just as caoutchouc alternately stretched 

 and recoiling becomes hot. 'But the heat thus developed 

 cannot be great. 



Moreover, the increase of temperature throughout the- 

 whole body, produced by active exercise, is but small ; the 

 great apparent increase of heat depending, in a great 

 measure, on the increased circulation and quantity of blood, 

 and, therefore, greater heat, in parts of the body (as the 

 skin, and especially the skin of the extremities), which, at 

 the same time that they feel more acutely than others any 

 changes of temperature are, under ordinary conditions, by 

 some degrees colder than organs more centrally situated. 



That the increased temperature of the skin during 



