90 PHYSIOLOGY OF THE NEW-BORN INFANT. 



ate amount of glycogen in the body at birth. On the second, third, 

 and fourth days the colostrum is entirely insufficient to supply the 

 needed energy; on the fifth day the milk flow is usually estab- 

 lished and subsequently the respiratory quotient is not far from 0.81, 

 indicating a katabolism in which somewhat over one-third of the 

 energy is derived from carbohydrate. This quotient is not far from that 

 found with normal individuals. Thus, in the study made by Benedict, 

 Emmes, Roth, and Smith, 1 in which 157 individuals (89 men and 68 

 women) subsisting upon a mixed diet were studied, the post-absorptive 

 katabolism showed a respiratory quotient of 0.81. Comparing this 

 average value with the respiratory quotients found with the new-born 

 infants, we may properly infer that the infant at birth has not an exces- 

 sive supply of glycogen in the tissues. We may further conclude that 

 the glycogen supply is somewhat rapidly exhausted on the first day and 

 it is not until the supply of milk from the mother's breasts is established 

 that we find a respiratory quotient indicating a considerable combustion 

 of carbohydrate. 



Further light is thrown upon this subject by a consideration of the 

 changes in body-weight during the first week. While it is practically 

 a routine in all hospitals to record the birth-weight of infants, it is 

 a well-known fact that in many instances the record may represent 

 the weight either before or after the meconium is passed, and that the 

 true physiological weight is not known. It is rarely that weights are 

 obtained from day to day, so that comparisons can be made and the 

 curve studied. As was stated in a previous section, there is at first a 

 distinct normal loss in body-weight with a subsequent rise; our obser- 

 vations, the results of which are given in table 11, have in consequence 

 a peculiar significance in this connection. 



The average body- weight for the first 7 days of life was as follows: 

 On the first day, with 74 subjects, 3.48 kg.; on the second day, with 

 64 subjects, 3.41 kg.; on the third day, with 62 subjects, 3.32 kg.; 

 on the fourth day, with 51 subjects, 3.34 kg.; on the fifth day, with 

 41 subjects, 3.43 kg.; on the sixth day, with 22 subjects, 3.51 kg.; 

 and on the seventh day, with 15 subjects, 3.54 kg. These figures are 

 not wholly comparable, as the weights were not obtained for the same 

 individuals during the whole period. Computations were made, 

 however, of the body-weight of 44 infants for both the first and second 

 days; these show that the body-weight for the first day was 3.61 kg. 

 and for the second day, 3.44 kg. There was therefore a loss of weight 

 during the first day of 170 grams. It is also clear that there was a 

 further distinct loss on the second and third days, which was followed 

 by an increase in the later days. It should be stated that during the 

 first few days the small amount of food taken would have relatively but 

 little effect upon the body-weight, although the sterile water, which was 



'Benedict, Emmes, Roth, and Smith, Journ. Biol. Cheni., 1014, 18, p. 139. 



