15 



METABOLIC PROCESSES. 

 Nitrogen Metabolism. 



The general effect of the preservative upon the assimilation and 

 excretion of nitrogen, as shown by the balance sheets, is not strongly 

 marked. It is evident, however, that there is some disturbance of 

 nitrogen metabolism, especially in inhibiting the absorption of nitro- 

 gen in the intestines, inasmuch as both summaries agree in showing 

 an increase of nonmetabolized nitrogen during the preservative 

 period. There was a much more marked disturbance in the case of 

 the subjects receiving sodium sulphite, those receiving sulphurous 

 acid (representing a smaller ingestion of S0 2 ) showing but little vari- 

 ation from normal conditions. 



Phosphoric-Acid Metabolism. 



The summaries show that there is quite a marked tendency on the 

 part of the preservative to derange in a measurable degree the metab- 

 olism of phosphoric acid. Sulphur both as sulphite and as free 

 sulphurous acid tends to increase the quantity of phosphoric acid 

 excreted in the feces and to decrease the quantity excreted in the 

 urine. It may, therefore, be said to have a decidedly inhibiting effect 

 upon the phosphoric-acid metabolism. 



Sulphur Metabolism. 



The most important point brought out by an inspection of the 

 sulphur balance sheets is the increased elimination of sulphur over 

 that ingested as preservative. There is an increase in both the urine 

 and feces, the increase in the urine during the preservative period 

 alone, in the case of the subjects receiving sodium sulphite, being 

 greater than the amount of preservative sulphur ingested, while in 

 the case of sulphurous acid the increase corresponds almost exactly 

 to the amount of preservative sulphur ingested. 



The increase in the feces, considering the same tendency shown in 

 the nitrogen and phosphoric-acid balances, can hardly be attributed 

 to an elimination of preservative sulphur through this channel, but 

 rather, as is before mentioned, to a decrease in assimilation and 

 absorption from the ingested food. This fact, together with the 

 probable increase in katabolic activities shown as regards the sulphur, 

 indicates that the administration of the preservative produced decid- 

 edly unfavorable effects. 



These tendencies are more marked in the case of sodium sulphite, 

 though the variations in the conditions of the experiment must be 

 considered in making this statement. 



[Cir. 37] 



