Energy Metabolism of Infants. 



15 



normal. One case of obesity thought to be of pituitary origin 

 was 10 per cent, from the normal average and hence may be 

 regarded as suspicious. The case of acromegaly was also 10 per 

 cent, below, and the myxedema 27 per cent, below. 



9 (94i) 



The energy metabolism of infants in relation to age and nutritive 



condition. 



By John R. Murlin. 



[From the Physiological Laboratory of Cornell University Medical 

 College, New York City.] 



Recent studies of the heat production of infants by Benedict 

 and Talbot, 1 Bailey and Murlin 2 and Murlin and Hoobler 3 indi- 

 cate a progressive increase from birth to the age of one year, 

 whether the metabolism is reckoned on the basis of weight or on 

 the basis of surface area (Meeh). 



On the basis of weight the average metabolism of 13 newborn 

 infants, determined while they were sleeping, is 1.87 calories per 

 kilogram and hour; of normal infants between the ages of two and 

 four months inclusive, it is 2.38 calories per kilogram and hour; 

 between 6 and 12 months the average is 2.45 calories per kilogram 

 and hour. 



On the basis of a square meter of skin surface the metabolism 

 of the newborns (up to 14 days of age) is, on the average, 25 

 calories per square meter and hour; of normal infants from two 

 to four months inclusive, 35 calories per square meter and hour; 

 and between six and twelve months the average is nearly 42 

 calories per square meter and hour. These differences on the 

 basis of surface area are based on the assumption that the surface 

 bears the same relation to weight (11.9 ^ (W) 2 ) in all. 



An analysis of all the observations on infants between the 

 ages of two months and one year studied by Howland, 4 Benedict 



1 Carnegie Institution of Washington, Publ. No. 201; also Amer. Journ. Dis. of 

 Children, 1914, VIII, p. 1. 



2 Proc. of this Soc., 1914, XI, p. 109. 



3 Ibid., 1914, XI, p. 115. 



4 Zeitschr.f. physiolog. Chemie, 191 1, LXXIV, p. 1; also Trans, of XVth Cong, on 

 Hygiene and Demography, 1912, II, Pt. II, p. 438. 



