CHARACTER OF THE KATABOLISM. 89 



RESPIRATORY QUOTIENT DURING THE FIRST WEEK OF LIFE. 



Table 11 also shows the respiratory quotients obtained for each day 

 up to the eighth day inclusive, the interval between successive daily quo- 

 tients being approximately 24 hours. The time when the breast-milk 

 appeared is designated by an asterisk (*) and when the milk was suffi- 

 cient in amount by the designation (J). Evidence that the infant was 

 clearly gaining weight was the criterion used in placing the designation 

 (t) . In the case of certain infants who were 3 or more days old when 

 the first observations were made, no designations have been placed on 

 the respiratory quotients, since apparently the breast-milk was already 

 established. Furthermore, when there was an interval of more than 

 36 hours between observations, either of the designations may have 

 been omitted. When there was no gain in weight, even if breast-milk 

 was recorded, it evidently was not sufficient; the designation (J) was 

 therefore omitted. All weights are without clothing. 



If we study the variations in the respiratory quotient found with the 

 new-born infants during the first week of life as shown in table 11, 

 we note a distinct tendency for the quotient to decrease after the first 

 day, reaching the lowest average of 0.73 on the third day. Thereafter 

 there was a tendency for the respiratory quotient to increase and on the 

 last 3 days the average was not far from 0.81. The average value 

 found with 74 infants on the first day was 0.80; with 64 infants on the 

 second day, 0.74; with 62 infants on the third day, 0.73; with 51 infants 

 on the fourth day, 0.75; with 41 infants on the fifth day, 0.79; with 22 

 infants on the sixth day, 0.82; with 15 infants on the seventh day, 0.81 ; 

 and with 9 infants on the eighth day, 0.80. It is quite obvious that 

 some factor entering into the nourishment of the infant produced a 

 change in the metabolism which raised the average respiratory quotient 

 from a minimum of 0.73 on the third day of life to 0.81 at the end of the 

 first week. 



According to the table of Zuntz and Schumburg, if we assume that 

 these are non-protein respiratory quotients, 0.73 would correspond to 

 a metabolism in which somewhat less than 10 per cent of the energy 

 was derived from carbohydrate and the remainder from fat, while a 

 quotient of 0.81 would correspond to a metabolism in which one-third 

 of the energy was the result of a carbohydrate combustion and two- 

 thirds was derived from a fat combustion. It is thus obvious that the 

 infant between the third and seventh days secured a supply of carbo- 

 hydrate which was not drawn from the body-material. This could be 

 derived only from the nourishment taken, usually in the mother's milk. 



The profound influence of the mother's milk upon the character of 

 the katabolism is shown by the fact that the time when the milk began 

 to appear in the mother's breasts, as indicated by the asterisk (*), 

 almost invariably coincides with the increase in the respiratory quo- 

 tient. On the first day of life the infant is subsisting upon the moder- 



