106 



PHYSIOLOGY OF THE NEW-BORN INFANT. 



Even these approximately minimum metabolism values show a heat- 

 production per square meter of body-surface which is considerably 

 lower on the first day than on the other days of the week. After the 

 first day the values remain essentially constant at 660 or 670 calories 

 until the eighth day, the values for 6 subjects on this last day averaging 

 702 calories. 



TABLE 13. Approximate basal metabolism of 

 infants during first 8 days after birth. 



If we turn again to figure 9, in which the absolutely minimum values 

 are shown, we find that there is a distinct tendency for the minimum 

 values for the days subsequent to the first day of life to group about a 

 vertical line corresponding to an average of approximately 640 calories 

 per square meter. If the limits of variation used with the other charts 

 are applied, it will be seen that practically all of the data for the last 6 

 days lie between 580 and 700 calories per square meter of body-surface, 

 the single exception being that of the 7-day-old infant No. 18, with the 

 extraordinarily low heat-production per square meter of 519 calories. 

 Aside from this particular case, therefore, all of the plotted values sub- 

 sequent to the first day of life lie inside of the 10 per cent variation 

 from the average value of approximately 640 calories. If the plus or 

 minus variation of 10 per cent is accepted as approximating a physio- 

 logical law, we may consider this a verification of the fact that after the 

 first 24 hours the heat-production of new-born infants during the first 

 week of life is approximately 640 calories per square meter of body-sur- 

 face, all values lying inside the limits of 10 per cent of this average. 



INFLUENCE OF LENGTH UPON THE BASAL KATABOLISM. 



In our study a large number of plots were made in an attempt to 

 establish some relationship between the metabolism, the body-surface, 

 length, weight, age, and even pulse-rate and body-temperature, as it 

 was believed that the data obtained in the research were sufficiently 

 extensive to justify a thorough search for a mathematical relationship 

 between the measured factors. In a close examination of the original 

 draft of figure 9, on which were noted the lengths of the infants repre- 



