36 ANALYSIS OF DISTURBANCES OF METABOLISM 



according as we are dealing with combustion of albumin, of fat, or of carbo- 

 hydrates. 



A complete, correct calculation of force-transference and heat-transfer- 

 ence is only possible if the excretion of carbon and of nitrogen is minutely 

 investigated for a considerable period of time, and then from both of these 

 the implication of proteids and of fat is estimated in metabolism. From the 

 hour or minute values, fixed conclusions cannot be drawn regarding the total 

 calory requirement ; they are therefore not final. We may hope, however, that 

 prolonged investigations of the interchange of gases (with Pettenkofer's or, 

 even better, with Hoppe-Seyler's apparatus) will give us more valuable con- 

 clusions for pathology, and decidedly broaden our knowledge regarding total 

 metabolism. 



The cases in which the entire interchange of forces in pathologic condi- 

 tions has been determined by sufficiently exact technical investigations are up 

 to the present time very few. "We owe them mostly to the labors of Eubner. 



In his researches in artificial nutrition carried on with Heubner ^ in a 

 normal and in an atrophic nursling, intake and output were directly estimated 

 in every way, and by calorimetric analysis it was possible to determine the 

 actual figures for the interchange of forces. It was shown that there is no 

 abnormal form of decomposition (force-transference) in the atrophic child. 

 The diet necessary for maintenance in the atrophic child and in the healthy 

 nursling correspond very well if we make allowance for small differences in 

 digestion and in the temperament of the children (influence of body rest, 

 motion and sleep). If they are given an excess of food, both utilize about 

 the same percentage for heat production, and about the same percentage is de- 

 posited in the tissues. The only peculiarity of the atrophic child is a lessened 

 power of intestinal absorption, and hence a more profuse production of feces. 



In a technically complete investigation of metabolism in an obese child, 

 Eubner ^ was unable to determine any diminution of interchange of forces. 

 Despite his pathologic predisposition, the boy required no less food than a 

 healthy boy of the same weight tested by Camerer. 



On the other hand characteristic differences in the processes of decompo- 

 sition were found by Sonden and Tigerstedt ^ in their investigations of metab- 

 olism in men of various ages. They conclude from these that there is a greater 

 life energy during youth, in contrast to the metabolism of the aged, in which 

 a lessened consumption may be recognized. The heat production amounted : 



In boys of 35.2 kilos weight to 1,322 calories 



In men of 67.8 kilos weight to 1,016 



In an aged man of 63.3 kilos weight to 934 " 



1 Rubner und Heuhner, " Die nattirliche Ernahrung eines Sauglings.'' Zeitschr. f. 

 Biol., Bd. xxxvi, p. 1. " Die kiinstl. Ernahrung eines normalen und eines atrophischen 

 Sauglings." Zeitschr. f. Biol., Bd. xxxviii, p. 315. 



2 Rubner, Beitrilge zur " Ernahrung im Knabenalter mit besonderer Berucksichtigung 

 der Fettsucht," Berlin, 1902. 



3 Sonden and Tigerstedt, " Untersuehungen iiber die Respiration und den Gesammt- 

 stoffwechsel des Menschen." Skand. Arch. f. Physiol., 1895, Bd. vi. 



