162 BIO-CHEMICAL JOURNAL 



alkalis in the tissues*). Furthermore, it has been shown, that in the 

 case of sulphuric acid, it is the absolute quantity rather than the 

 dilution which increases the rate of autolysis. 



From these results we arrive at the following conclusion as to 

 the function of nitrogenous foodstuffs in nutrition : 



In order to maintain nitrogenous equilibrium, nitrogenous food stuffs must 

 be ingested in such quantities, and in such form that the ammonia produced 

 therefrom in the digestive tract is sufficient to maintain the intracellular 

 alkalinity of the liver and probably other tissues. 



In order to fully understand this mechanism it is of importance 

 here to consider the products other than nitrogenous bodies which arc 

 formed during autolysis. Magnus-Levy 3 has shown that the liver on 

 autolysis under the most stringent precautions for asepsis yields carbonic 

 and other organic acids, such as lactic acid ; furthermore, the degrada- 

 tion products of fats and carbohydrates are of acidic nature all would 

 on hydrolysis or oxidation produce acids ; it matters not, however, for 

 the purposes of the present argument whether the acid products are 

 produced from the stored-up food-stuffs, or from the bioplasm itself. 



We have, therefore, two classes of products producible, viz., non- 

 nitrogenous acidic bodies and nitrogenous bodies ; the production of 

 the latter class, it has been shown, is stimulated by the presence of the 

 former. In well-nourished animals there is, however, always an excess 

 of ammonia present, hence in this case the tissues will not become acid 

 in vivo. The excess disappears gradually, however, if the animal is 

 deprived of food. A certain stage will then be reached, when the 

 production of acid exceeds the amount of ammonia available for 

 neutralization ; the autolytic enzyme then comes into play, liberates 

 amino-acids, etc., which in their turn pass the alimentary tract, and by 

 means of the metabolic processes there taking place liberate ammonia, 

 which again inhibits the production of nitrogenous degradation products. 

 Degradation of tissue should proceed, therefore, at a definite uniform 

 rate. From the preliminary experiments carried out it seems that the 

 production of acids is inhibited by the presence of acids ; we have, 



* Ammonia is also responsible for the production of sodium carbonate (NH*) CO 3 + 2 NaCl = 



