CONCLUDING REMARKS 61 



of alcohol, does it so constantly strike us that the results of research are con- 

 flicting and permit different explanations ? 



Because the whole process is without doubt quite different from our ordi- 

 nary dynamic conception of it. Alcohol, after absorption, is not only decom- 

 posed into carbonic acid and water, and thus converted into a definite amount 

 of heat, but, moreover, it enters the protoplasm of the cells where all oxida- 

 tion takes place, and there modifies the destruction of the protoplasm. 



For the same reason the carbohydrates and fats do not act isodynamically 

 in regard to albumin saving, as would be the case if the supply of heat repre- 

 sented by them became free in the circulation. In fact the carbohydrates 

 are more active than the fats in the physiologic experiments. 



By the appearance of acetone bodies after the complete withdrawal of 

 carbohydrates, pathology indicates that not only quantitatively, but also quali- 

 tatively, the destruction of the cell protoplasm occurs in different ways, accord- 

 ing to whether the carbohydrate molecule or the fat molecule is found in the 

 cell which dominates the processes of decomposition. 



It has already been mentioned that the newer facts regarding the condi- 

 tions and the occurrence of the accumulation of albumin are very difficult to 

 reconcile with Voit's laws of albumin metabolism. 



The fact that gelatin, and as Mann ^ has lately shown, also elastin, even 

 although they are inferior to fat as calory carriers, are far superior as albu- 

 min savers, certifies beyond doubt that the nitrogen-containing food mole- 

 cule of the body-cell in which decomposition takes place brings with it 

 something else than the calories — something which influences metabolism, 

 independently of the calories which it brings. 



Analogous with this is the remarkable observation of Loewi,^ who fed a 

 dog with N-free starch and cane sugar as the sole carriers of nitrogen and 

 with soluble products of continuous pancreas digestion until the complete 

 disappearance of the biuret reaction. Thus he managed to produce nitrogen 

 equilibrium. Therefore, the dog must have formed albumin synthetically 

 from the nitrogen carriers in solution (from amido acids, ammonia, purin 

 bases and hexon bases). 



This proof was necessary to throw light upon many physiologic and patho- 

 logic processes of metabolism. I shall mention only one more : 



According to the dominant teaching, it was formerly very difficult to 

 answers questions which arose as to the origin of muscular power. Voit was 

 the first to show that increased muscular labor is not expressed by a decided 

 increase of albumin decomposition (in the balance of metabolism), and, in 

 opposition to the views of Liebig who believed albumin decomposition to be 

 inseparably combined with the activity of the organs, regarded the nitrogen- 

 free food products as the source of energy from which the organs, without 

 suffering in their substance, derived energy for their functions. 



Now the newer investigations of Caspari actually show an accumulation 



1 Mann, " Ueber das Verhalten des Elastins im Stoffwechsel des Menschen." Arch, 

 f. Hygiene, Bd. xxxvi, p. 166. 



^Loewi, "Ueber Eiweisssynthese im Thierkorper." CentralU. f. Physiol., Bd. xv, 

 p. 590. 



