646 



JOHN E. MUELIN 



in some instances the heat production (based on carbon dioxid) in their 

 subjects twenty-one hours after food was slightly "greater even in periods 

 of complete muscular repose" than immediately after food. 



4. Influence of Age on Basal Metabolism. Basal metabolism is the 

 term used to describe the fundamental requirements of the body for energy 

 when it is resting, fasting, and kept comfortably warm. It is the lowest 

 normal metabolism. With the infant this lowest metabolism will always 

 occur during sleep and at that distance from feeding time just preceding 

 the point where hunger becomes so acute as to induce crying or some other 

 form of activity. 



In connection with the dynamic action of food we have chosen to 

 speak of the lowest metabolism yet attained as the minimal rather than the 

 basal metabolism ; for we have yet to learn of the details of this subject. 

 However, the minimal metabolism ordinarily seen in the infant, i. e., the 

 sleeping metabolism of the recently fed infant, cannot be much greater than 

 the basal metabolism if food really exercises so small an influence on total 

 heat production as it seems to. We shall not go far wrong then in speak- 

 ing of the minimal metabolism observed in infants of different ages as 

 the true basal. 



Benedict and Talbot first demonstrated the influence of age on the 

 basal metabolism per unit of area, although not recognizing the fact, in 

 the following table: 



TABLE 33 



HEAT-PRODUCTION PER SQUARE METER OF BODY-SURFACE (Meeh Formula) FOR NORMAL 



INFANTS 



The next year Murlin and Hoobler brought together their own data 

 from normal infants and those of Benedict and Talbot published in their 

 second paper and conclusively showed that both on the basis of surface 

 area and weight the metabolism of infants above six months of age is sig- 

 nificantly higher than that of infants four months and less. The results 

 are condensed in the following table : 





