ANIMAL HEAT. 577 



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. 



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.; 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 C. during the 

 first few hours after birth, and then rises 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 of 

 life the temperature may undergo considerable variations^ and that it is readily 

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

 stances which have little or absolutely no influence upon the temperature of 

 the adult. 



The mean temperature of the female is said to be slightly lower than that 



37 



