ON NITRIFICATION 497 



carbon assimilation by the second. Expressing these functions 

 by means of a diagrammatic representation, figure 3 is obtained. 



According to the above diagram, when the cell carbon is suffi- 

 ciently large the process of chemosynthesis is endless, unless one 

 of the end products is removed. Thus in the case of narcosis 

 of the cell, respiration continues with degeneration and complete 

 consumption of the available cell carbon, and when all such were 

 consumed death of the cell would result. This condition of nar- 

 cosis may be brought about by an excessive concentration of food 

 substances or of cellular byproducts, with the cellular breakdown 

 demonstrated by Bonazzi (1919-a) and by Gibbs (1919) and 

 physiological inertia as has been shown by BouUanger and 

 Massol (1903, 1904); 



When the supply of free carbon dioxide is nil throughout the 

 experiment the respiration process regulates chemosynthesis and 

 the products of nitrosofermentation are in immediate relation 

 to the quantity of cell substance respired and, since no carbon 

 assimilation can follow, death of the cells results. 



When ammonium carbonate is used as a source of carbon and 

 the free carbon dioxide is continually removed by means of an 

 absorbent there is a slow accumulation of the carbamate and 

 fast removal of the ionized CO2 (Macleod and Haskins 1906). 

 Together with this there is a depletion of all the respirable stores 

 in the cell, so that in the system the following substances will be 

 found: (NH4)2C03, NH4CO0NH0, cells, traces of respired C 

 compounds, and NH3. Since it has been experimentally proved 

 that the cells cannot, under these conditions, assimilate this 

 nitrogen (experiment 244, 246 and 249) the interpretation to 

 be given to these facts is that the free carbon dioxide is closely 

 tied up with the nitrogen nutrition of the organism and that in 

 this condition it distills too fast for the cells to utilize it. It 

 follows that if this distillation is prevented by mechanical means, 

 there should then be possible some nitrification and chemosyn- 

 thesis: this is what actually takes place in experiments fulfilling 

 the required conditions. ^ 



3 Meyerhoff in Pfluger's Archiv f. Ges. Physiol. 1917. 166, 240-280, found 

 nitrification to proceed in the presence of 10 per cent NaOH solution, and the 



