524 



A MANUAL OF PHYSIOLOGY 



temperature is certainly due in part to the increased work of 

 the alimentary canal, but is also connected with the increase 

 of metabolic activity which the entrance of the products of 

 digestion into the blood brings about. The solution of the 

 solids of the food by the digestive juices is associated with 

 absorption of heat, as has been observed in artificial digestion, 

 and even in a case of gastric fistula. The increased heat- 

 production, however, is more than sufficient to prevent any 



fall of body temperature 

 from this cause. The 

 cause of the daily varia- 

 tion of temperature has 

 been much discussed. 

 There is no doubt that 

 several factors are con- 

 cerned, the most im- 

 portant being the varia- 

 tion in the amount of 

 contraction of the skele- 

 tal muscles and the in- 

 fluence of food. This 

 is shown by the fact 



that in persons who 

 FIG. ^-CURVE OF COOLING AFTER DEATH WQrk ^ night and sleep 



Time marked along horizontal, and temperature during the day the Curve 

 along vertical axis. At a ether and chloroform ,.f t Arnr > Ara t lir ~ ic TV>- 

 given to kill animal ; death, as indicated by stoppage O1 teinperdlUI 

 of the heart, took place at b. The dotted line versed, 

 shows the course the curve would have taken if 

 death had occurred at the moment the anaesthetics As to the relation OI 



age and sex to tempera- 

 ture, it is only necessary to remark that the mean temperature 

 both of the young child and of the old man is somewhat higher 

 than that of the vigorous adult; but a point of more importance 

 is the relative imperfection of the heat-regulation in infancy 

 and age, and the greater effect of accidental circumstances 

 on the mean temperature. Thus, old people and young 

 children are specially liable to chills, and a fit of crying may 

 be sufficient to send up the temperature of a baby. The tem- 

 perature of women is generally a little higher than that of 

 men, and is also, perhaps, somewhat more variable. 



