CHAP. XXX.] TEMPERATURE OF HUMAN BODY. 419 



and 111 F., the mammalia having the lower and birds the higher, 

 in strict accordance with the above-mentioned circumstances. A 

 bird, for its weight, consumes much more oxygen, and sets free 

 much more carbonic acid, while it maintains in the same medium a 

 higher temperature, than a mammal. Finally, some degree of 

 warmth is evolved by the egg in its development during incubation. 

 In this process, oxygen is absorbed, and carbonic acid exhaled 

 through the calcareous envelope. 



The amount of heat developed in the animal organism, depends 

 very much upon the nature and quantity of the food. The carbon 

 of the food in its slowly effected union with oxygen within the 

 organism, gives out probably as much heat as if the same quantity 

 were burnt in oxygen gas. The development of animal heat will, 

 therefore, in great measure depend upon the activity of the 

 functions of respiration and circulation. 



The greater part of the oxygen which an adult consumes in the 

 twenty-four hours, instead of remaining in the body, thereby in- 

 creasing its weight, unites with carbon and hydrogen, and is 

 removed in the form of carbonic acid and water. The remainder 

 enters into combination with other elements, and compounds are 

 formed which are removed by the excreting glands. In these com- 

 binations a large amount of heat is developed, ranging in amount 

 according to the conditions before referred to. 



Temperature of the Human Body. The heat of the interior of the 

 body of those parts which are most accessible to our instruments 

 of measurement, as, for instance in the axilla, within the mouth or 

 rectum, is found to be about 97 or 99 F. ; more frequently the 

 latter. The temperature is, however, liable to variation according 

 to circumstances which modify the amount of heat generated 

 within the body or the rapidity of its loss. Independently of this, 

 however, great differences have been found to exist in the temper- 

 ature of different parts, according to the rate of their cooling, their 

 vascularity, distance from the centre of circulation, etc. A good 

 idea of this will be derived from the following Table of Dr. 

 Edwards. He examined a strong man, at rest, in July, the air 

 being at 71 F., and found 



Mouth and rectum .... 102 



Hands 99'5 



Axillae and groin .... 99" 



Cheeks 96 



Feet 96 



Skin of Epigastrium .... 95 



