PART III. 

 DISCUSSION OF RESULTS. 



In a recent study of the metabolism of diabetics in this laboratory, 

 it was found that the experiments were much lessened in value because 

 of the lack of suitable normal controls. This led us to believe that our 

 best service to pediatrics would be to determine the normal metabolism 

 of infants. Accordingly, while a few observations were made with dis- 

 tinctly pathological cases, our data were secured for the most part with 

 normal or under-weight infants. 



One important problem in such an investigation is the relationship 

 between muscular repose and metabolism. The graphic registering de- 

 vice for recording the muscular movements of the infant gave us an ex- 

 ceptionally good opportunity to obtain data regarding this relationship, 

 which was made an object of special study in this investigation. 



Furthermore there is a wide difference of opinion among physiologists 

 as to whether or not during sleep there is a lowered metabolism, some 

 writers maintaining that it is possible for a man to relax his muscles 

 voluntarily so as to have a metabolism while awake as low as that during 

 sleep, the sleep of itself having no influence upon the metabolism. With 

 infants it is almost impossible to obtain periods of muscular repose 

 while the infant is awake and it was recognized at once that only those 

 periods when the infant was asleep could reasonably be looked upon as 

 periods of complete muscular rest. It was hoped, however, that certain 

 periods might throw light upon the effect of sleep upon metabolism. 



The influence upon metabolism of the ingestion of food also received 

 some attention in this research as an increased metabolism following 

 the ingestion of protein, fat, or carbohydrate has been noted in many 

 observations made with adults. This increase in the metabolism has 

 been variously ascribed to the mechanical work of digestion, to the 

 so-called specific dynamic action of the foodstuffs, or, as is now the 

 belief in this laboratory, to the stimulating effect of certain substances — 

 the specific katabolic stimuli — absorbed from the food material through 

 the alimentary tract, and there carried by the blood to the cells to stim- 

 ulate them to greater activity. Reasoning from the results obtained with 

 adults, an infant receiving nutriment should have a greater metabolism 

 than when he is without food; and it was hoped that experiments 

 could be made with normal infants in which the influence of the 

 ingestion of food could be more carefully studied. Difficulty was found 

 at the outset in securing periods of quiet with infants under any con- 

 ditions, but greater difficulty was had when the infants were not fed. 

 Our experience, we admit, is very limited and we hope to profit by the 

 suggestions of other observers, particularly Schlossmann and Mursch- 

 hauser, in securing further aid in this important study. The data we 

 have thus far obtained are somewhat fragmentary and by no means 

 convincing; in fact, they hardly justify an extended discussion. 



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