Bodily Labour upon the Discharge of Nitrogen. 499 



It is curious to observe how on these days of fast, despite different 

 circumstances, and the fact that the fast of February 15th was pre- 

 ceded by a fast on the previous day, how great is the similarity in 

 the daily discharge, for again on July 5th, 1882, a day of fast pre- 

 vious to commencing an experiment, the discharge was 9*10 grams, 

 and on July 17th, at the conclusion of the same experiment, 9*46 grams 

 were discharged. 



This gives an average discharge on fast days of 9*23 grams of nitro- 

 gen by the urine. 



Now turning to the table showing the daily balance of nitrogen in 

 the food and excreta, we find in the first part of this experiment that 

 assuming, as I have endeavoured to show we have some right to 

 assume, that the daily ingestion of nitrogen was practically the same 

 as during the experimental diet, it will be seen that I started with 

 a deficit of 0*69 gram, which became a balance of 3'0l grams on 

 February 10th. After considerable fluctuations on the 8th and 9tb, 

 the fast of February 11th reduced the balance to .a deficit of 8*37 grams, 

 that is to say, 11*38 grams were removed from the body, and it is a 

 very extraordinary fact, though I fear accident has something to do 

 with it, that the total nitrogen discharged on February 11th by urine 

 and fasces amounted to 11*38 grams precisely. Supposing this to be 

 a fact, and not a mere coincidence, the whole of the nitrogen excreted 

 on February 12th should be represented by the difference between 

 the supposed ingesta and this deficit of 11 '38 grams, that is to say, 

 6*26 grams is all that the body can afford ; but this is not the case. 

 In this case as in other instances the deficit is not made up at once, 

 but slowly ; 1*94 grams were retained on February 12th, and 

 1'85 grams on February 13th, thus reducing the deficit to 4'58 grams. 

 On February 14th the fasting raised it again to 15'16 grams, and the 

 fast of February 15th to 24*42 grams, and this closes the first period. 



Whatever may be the value of calculations based on this hypothesis 

 of similarity of nitrogenous ingestion, it is, I think, only fair to 

 assume that there was a deficit, put it even as low as 10 grams. On 

 February 15th I began the experimental diet, with the exception of 

 so much as reduced the daily ingestion of nitrogen to 17'05 grams, and 

 despite the apparent needs of the body, out of 17'05 grams taken in, 

 16*65 grams were discharged. Again on February 17th the deficit 

 reached its maximum of 25*16 grams, gradually diminishing up to 

 February 24th, when it amounted to only 9*68 grams, whilst on 

 February 25th the excretion was so small, that the deficit fell to 

 4*99 grams, to be increased on the following day to 5*29 grams. The 

 fast of February 27th brought it up to 13*95 grams, which was 

 reduced on March 1st to 6*21 grams, rose again to 7*30 grams on the 

 2nd, and fell to 5*50 grams on the 3rd, the concluding day of the 

 experiment. 



