6 ANALYSIS OF DISTURBANCES OF METABOLISM 



metabolism that arise from them, and by their combustion in metabolism 

 becomes living force, Eubner has calculated at 4.1 calories for one gram of 

 albumin, 9.3 calories for one gram of fat, 4.1 calories for one gram of carbo- 

 hydrate. 



These are the figures which are utilized as standards in all clinical inves- 

 tigations in metabolism (the correspondence of the value for albumin and 

 carbohydrate is quite accidental). 



In these values force is expressed in units of the heat which is generated in 

 the organism when by combustion of the individual food products their end 

 products in metabolism are produced. The loss which occurs in the intestines 

 by insufficient absorption of the food is not considered here. They are, there- 

 fore, gross values (large calories). To convert them into pure calories, Eub- 

 ner has calculated a subtraction of 8 per cent, from the average heat value of 

 the feces on a mixed diet. His latest investigations, by means of the direct 

 calorimetry in man, have shown that the calculation obtained from chemical 

 analysis of the standard figures in derived heat corresponds almost perfectly 

 with the amount of heat in calories taken directly from the calorimeter. The 

 method commonly used in the clinic to calculate the energy transference from 

 the calory value of the food introduced is therefore accurate, if no severe 

 disturbances in absorption are present. 



B. THE METHODS FOR ESTIMATING THE CALORY REQUIREMENT 



OF THE BODY 



The method in use in Voit's laboratory for determining the degree of 

 metabolism in a healthy individual under various conditions of nutrition is 

 by the comparison of intake and output in a trial period of twenty-four hours. 

 This presupposes that the body within this time rids itself of the total end 

 products of metabolism that have arisen from the decomposition of organic 

 substances. This supposition is quite correct for excretion in the respired air 

 and in the urine. To estimate the contents of the feces (the discharges usu- 

 ally occurring later here), we need to mark in some way the beginning of the 

 experimental period. This is usually accomplished without difficulty and 

 with sufficient exactness by the administration of from 10 to 15 grams of 

 powdered charcoal or 0.3 gram of carmin at the beginning and at the end of 

 the metabolism investigation. This method in its high technical completion 

 was the sine qua non for the quantitative investigation of metabolism at the 

 bedside. 



An accurate estimate of the food ingested during the period of trial and 

 of the carriers of energy contained in it (albumin, fat and carbohydrates) is 

 necessary. The excretions, i. e., the urine, the feces and the expired air, are 

 measured with exactness, and analyzed as to the amount of nitrogen and car- 

 bonic acid which they contain. Prom a comparison of ingesta and excreta 

 the balance is obtained. 



I shall quote an example of one of Voit's experiments : A workman weigh- 

 ing 09.5 kilograms took in the form of meat, egg, . albumin, milk, bread, lard, 

 butter, flour and sugar a total of 137 grams of albumin, 117 grams of fat, and 



