118 PHYSIOLOGY OF THE NEW-BORN INFANT. 



and the apparent scant supply of colostrum, leads us to expect, a 

 priori, that there is a lack of balance between intake and output. To 

 attempt any readjustment demands either (1) a reduction of the energy 

 output or (2) a more adequate food-supply, or a combination of both 

 factors. 



THE CONSERVATION OF ENERGY. 



The energy output depends largely upon the heat-regulation of the 

 body. The values previously presented have indicated that this heat- 

 regulation is very imperfect during the first day after birth, since both 

 minimum and maximum values for the basal metabolism per unit of 

 weight or surface area are noted on this day. 1 Important supple- 

 mentary evidence as to a greatly disturbed heat-regulation may be 

 found in a study of the body-temperature of these infants, for body- 

 temperature is the resultant of thermogenesis and thermolysis, and if 

 the latter prevails, there is a falling temperature. The well-known 

 factors influencing body-temperature in the adult, such as muscular 

 activity and exposure to a temperature environment differing greatly 

 from that of the body, are immediately recognized as factors entering 

 into the early life of the new-born infant, thus making a consideration 

 of the fluctuations in the body-temperature imperative in any adequate 

 discussion of the problem of heat-regulation in the body of the new- 

 born infant. 



BODY-TEMPERATURE. 



The body-temperature of these infants was recorded in practically 

 all instances just before and just after the observation of the respira- 

 tory exchange, and the data obtained are given with the other statistical 

 data in table 9. 2 In many of the observations on the first day after 

 birth, the body-temperature rose while the infant was inside the respi- 

 ration chamber. It would appear, therefore, that the effect of the 

 labor, the bath, and the exposure incident thereto was to lower the 

 temperature below normal. High temperatures were rarely noted with 

 any of the infants, but occasionally very low records were obtained 

 when there had been undue exposure, such as in the bath given before 

 the observation of the respiratory exchange. The low temperature due 

 to this previous exposure persisted for some time, but the temperature 

 gradually attained the normal height for an infant of this age. 



In order that a more definite comparison may be made of the body- 

 temperature records during the first day after birth with those obtained 

 in the days following, the average rectal temperature of our infants for 

 each of the first 8 days is given in table 20. To study more closely 

 the temperature for the first day, we give also the records obtained with 

 infants studied before they were 12 hours old and those studied between 

 the twelfth and twenty-fourth hours. On the day of birth 48 infants 



'See figures 7, 8, and 9, pp. 103, 104, and 105. 2 See pages 46 to 79. 



