40 



ARON. 



I obtain figures confirming this rule from some of my experiments on 

 amply fed dogs. If we compare the figures for a period of fifty days the 

 following values are obtained: 



Dog. 



Calories. 



Increase. 



Increase. 



Calories 

 taken per 

 gram in- 

 crease. 



From— 



To- 



B . . 



19,950 



13, 925 



9,500 



10,750 



Grams. 

 2250 

 2220 

 1265 

 1785 



Grams. 

 3820 

 3220 

 2015 

 2623 



Grams. 



1,570 



1,000 



780 



838 



12.7 

 13.9 

 16.4 

 15.6 



C 



VIII 



XII 





However^ if we compare the well and poorly nourished dogs of the 

 same litter, the law does not hold. It seems clear that an animal gaining 

 1,000 grams during fifty days needs fewer calories for this gain than 

 one gaining 1,000 grams in one hundred or one hundred and fifty days. 

 In the first instance the animal needs to be maintained for only one-half 

 the time as in the latter. Therefore, it seems nearly impossible to give 

 any mathematical law, so long as the time factor can be varied freely. 



INCREASE IN WEIGHT AS AN INDEX TO GROWTH WITH SPECIAL REFERENCE TO 



CHILDREN. 



One of the most striking results of our experiments is the demonstration 

 that lack of increase in weight in a growing animal does not indicate 

 a lack of growth, but starvation, accompanied by loss of body substances. 



This is of importance in practical pediatrics. We learn from it that 

 a child which does not increase in weight or increases slowly is so under- 

 nourished that part of its own body substances are being consumed. We 

 can go even further in our conclusions. If a child does not present 

 the weight which we have a right to expect at its age, assuming that it 

 was born with a more or less normal weight, this child's body does not 

 have the normal composition. It will contain a higher percentage of 

 bones, a lower content of fat and muscle tissues, and a higher content of 

 water and the caloric value of a unit of its body weight will be below 

 that of a normal child. To feed such a child properly it is necessary 

 first to attempt to replace water in its body by fat and protein. There- 

 fore, it can use energy above the amount required for maintenance with- 



