406 Influence of Inanition on Metabolism. 



While in Folin's metabolism experiments there was a marked parallelism 

 between the excretion of creatinine and neutral sulphur, in these experiments 

 the total creatinine remains constant during the fast, and the neutral sulphur 

 persistently decreases. The preformed creatinine on the other hand more 

 nearly follows the neutral sulphur elimination. 



The results here obtained during inanition serve to complicate the matter 

 still further, and there is obviously much research to be done upon the problem 

 of neutral sulphur before definite conclusions can be drawn. 



PHOSPHORUS. 



Under normal conditions, with food, material amounts of phosphorus are 

 excreted in the feces as well as in the urine. In fasting experiments, however, 

 and specifically in the experiments under discussion in this report, only the 

 phosphorus excretion of the urine has been adequately studied. The difficulties 

 experienced in the proper separation of fasting feces precludes any discussion 

 of the amount of phosphorus excreted through the feces during fasting. 



The phosphorus of the urine, under normal conditions when food is given, 

 may originate from several sources : First, preformed phosphates of the food, 

 such as the phosphates of milk; second, phosphorus of the nucleo-proteids of 

 food ; and third, phosphorus already stored in the body, including of course the 

 calcium phosphate of the bones, which might possibly become disintegrated to 

 a certain extent. In fasting urine, especially, this last factor should not be 

 overlooked. 



Determinations of phosphorus in urine were common in the earlier fasting 

 experiments, and since the method, i. e., volumetric titration with uranium 

 salts, has not been materially modified, the results are much more nearly 

 comparable than is the case with almost any other element involved in 

 katabolism. While there is not complete uniformity on the part of writers in 

 expressing the results of phosphorus determinations, it has been common to 

 express them in the form of phosphorus pentoxide (P 2 5 ). For the reason set 

 forth in the discussion of sulphur in the preceding section, it has been thought 

 desirable to report the elimination of phosphorus expressed as the element in 

 subsequent experiments. The daily amounts of phosphorus (as P 2 5 ) elimi- 

 nated in the urine of fasting subjects are presented in table 212. For subse- 

 quent discussion the ratios of nitrogen to phosphorus pentoxide (N/P 2 B ) are 

 given in heavy-faced type in the same table. 



The phosphorus pentoxide excretion is by no means uniform in the three 

 experiments with Succi. For example, there were but 1.46 grams excreted on 

 the fourth day of fasting in the Naples experiment, while there were 2.54 grams 

 on the corresponding day of the fast in Vienna. On the whole, there was a 

 much larger amount of phosphorus excreted per day at Vienna than during 

 either of the two earlier fasts. In Cetti's experiment, the phosphorus excretion 



