ANIMAL HEAT. 469 



and to Jaeger 37.3° C. The mean axillary temperature may be put down as 

 being about 37.1° C. (98.8° F.), the normal limits being 36.25° to 37.5° C. 

 (97.2° to 99.5° F.) The temperature in the mouth is about 0.2° to 0.5° C. 

 higher than in the axilla, in the rectum from 0.3° to 1.5° C. higher, and in the 

 vagina from 0.5° to 1.8° C. higher. 1 



The temperature of different tissues varies. Davy, as results of observa- 

 tions on a fresh-killed sheep, gives the temperature of the brain as about 40° 

 C.j of the left ventricle 41.67° C. ; of the right ventricle 41.11° C.; of the 

 liver 41.39° C. ; of the rectum 40.56° C. According to Bernard, the liver is 

 the warmest organ in the body, and then the following in the order named — 

 brain, glands, muscles, and lungs. 



The temperature of the blood varies considerably in different vessels. In 

 the carotid it is from 0.5° to 2° C. higher than in the jugular vein; in the 

 crural artery, from 0.75° to 1° C. higher than in the corresponding vein ; in 

 the right side of the heart about 0.2° C. higher than in the left; in the hepatic 

 vein 0.6° C. higher than in the portal vein during the intervals of digestion, 

 and as much as 1.5° to 2° C. or more during periods of digestion ; the venous 

 blood coming from internal organs is warmer than the arterial blood going to 

 them, but the blood coming from the skin is cooler than that going to it ; the 

 blood coming from a muscle in a state of rest is about 0.2° C, and during 

 activity as much as 0.6° to 0.7° C, warmer than that supplied to the muscle. 

 The mean temperature of the blood as a whole is about 39° C. (102° F.); of 

 venous blood about 1° C. (1.8° F.) lower than of arterial blood. The warm- 

 est blood in the body is that coming from the liver during the period of diges- 

 tion; the coolest blood is that coming from the tips of the ears and nose and 

 similarly exposed parts. 



Conditions affecting- Bodily Temperature. — The mean temperature of 

 the body is subjected to variations which depend chiefly upon age, sex, consti- 

 tution, the time of day, diet, activity, season and climate (surrounding tem- 

 perature), the blood-supply, disease, drugs, the nervous system, etc. 



The temperature of a new-born child (37.86° C.) is from 0.1° to 0.3° C. 

 higher than that of the vagina of the mother; it falls about 1° < '. during the 

 first few hours after birth, and then ii>cs within the next twenty-four hours to 

 about 37.4° to 37.5° C The mean temperature of an infant a day or two 

 old is about 37.4° C. It very slowly sinks until full growth is attained, when 

 the normal mean temperature of adult life is reached (37.1° C), a standard 

 which is maintained until about the age of forty-five or fifty, when it declines 

 until about the age of seventy (36.8° C), and then slowly rises and approaches 

 in very old people (eighty to ninety years) the temperature of very young 

 infants (37.4° C). It is important to observe that during the early weeks "I 

 life the temperature may undergo considerable variation-, and thai it is readily 

 affected by bathing, exposure, crying, pain, sleep, etc, and by many circum- 



1 The average figures of the mean daily temperatures obtained from tin- records of ;i num 

 ber of investigators are, mouth, o<5.S7° ; axilla, 3d. 94° ; ami rectum, 37.02°. The mean figures 

 for the twenty-four hours are in each rase about 0.2° less. 



