Nitrogen in Urine. 369 



grams. In comparing Prausnitz's results with those obtained in this laboratory, 

 it is important to note that while wide differences in size, weight, and dietetic 

 habits existed in Prausnitz's subjects those used in the Middletown experiments 

 were as a rule college students eating more nearly the same fare. 



The approaching constancy in the nitrogen elimination found on the second 

 day of the fast with different individuals would incline one to the belief that 

 on the third day the constancy would be even greater, yet an inspection of the 

 results in table 197 shows that the variations ranged from 10.98 in experiment 

 No. 77 to 15.04 in experiment No. 69. In the four experiments with S. A. B., 

 the variations were from 10.98 to 13.10 grams, or a little over 2 grams. The 

 average elimination for the six experiments was 13.08 grams. 



Five experiments were made in which the fast was continued for 4 or more 

 days. In these the nitrogen excretion varied from 10.39 to 12.97 grams, 

 the average elimination for the five experiments being 11.44 grams. In the 

 four experiments with S. A. B., the excretion varied from 10.39 to 11.63 grams, 

 a difference of 1.24 grams. Not only is the variation for all the experiments 

 much less, therefore, than on the previous days, but in different experiments 

 with the same subject, there is a tendency for the nitrogen excretion to approach 

 constancy on the fourth clay. 



Two experiments, both with S. A. B., continued for 5 or more days. The 

 nitrogen in these experiments amounted on the fifth day to 9.98 and 10.87 

 grams, averaging 10.43 grams. One experiment continued during the sixth and 

 seventh days and on these days there were excreted 10.74 and 10.13 grams of 

 nitrogen, respectively. 



Variations in nitrogen elimination as the fast progresses. While as has been 

 seen from the previous discussion, the gross fluctuations in the nitrogen excre- 

 tion for the first day of different fasts render any interpretation of these 

 results for short fasting experiments difficult, in the longer fasts the disturbing 

 features of the first day are eliminated and the data are such as to permit of 

 definite conclusions. In the majority of the experiments, there is an excretion 

 of at least 2 grams more on the second day than on the first. In experiment 

 No. 85, there was a greater excretion on the first day by 0.02 gram which, 

 however, may well be within the limit of experimental error. 



On the contrary, Prausnitz (5) found in three out of fifteen cases a dimin- 

 ished excretion on the second day. Of the thirteen fasting experiments cited 

 in table 196 there was an increased nitrogen elimination on the second day of 

 fasting in only three instances. The lack of harmony between these results and 

 those obtained in the Middletown experiments can not readily be explained. 

 Physical condition, previous dietetic habits, muscular exercise and other factors, 

 yet too little known, may all have contributed to this result. The great 

 uniformity in the results of the Middletown experiments would tend to uphold 

 the view, that with like bodily activity and environment, the results should all 

 be strictly comparable. 

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