500 Mr. W. North. The Influence of 



Variations from the Experimental Diet, February 16 to March 2. 

 Experiments, February 16 to March 2, 1883. 



Date. 



Quantity. 



Food. 



"Nitrogen. 



p 2 o 5 . 



H 2 S0 4 . 



NaCl. 





Feb. 16 . . 



grams. 















60 



Potato 



0-586 



0-295 



0-126 



0-306 



Omitted 



„ 17.. 



200 



Flour 



3-403 



0-680 



0-032 





Omitted 



„ 20 . . 



10 



Milk 



0-147 



0-070 



0-003 



403 



Added 



Mar. 2 . . 



20 



J ulienne 



354 



0-162 



0-088 



0-057 





„ 2.. 



30 



Meat 



4-065 



0-567 



0-018 



0-051 



| Omittsd 



„ 2.. 



20 



Potato 



0-192 



0-098 



0-022 



0-102 





I may here remark that the total nitrogen value of the food omitted 

 on February 16th and 17th, and on March 2nd, was 8*60 grams ; exact 

 particulars are stated in the table already given. So that had the full 

 diet been taken on these days there would have been a balance of 

 3*1 grams in the body, or rather it would have been possible. During 

 the whole of the latter part of this experiment, that is from Feb- 

 ruary 10th onwards, my sensations were such as I have learned to 

 associate with the repair of waste, and it would have been exceedingly 

 interesting to have continued the experiment yet another ten or twelve 

 days, in order that I might have had the opportunity of investigating 

 the effect of muscular labour, or of starvation upon my body, at this 

 time presumably in a state of nitrogenous equilibrium. 



I do not feel justified in again subjecting myself to prolonged star- 

 vation, that is to say starvation extending over four or five days ; but 

 I think that similar results can be obtained, as far as the nitrogen is 

 concerned, by mere twenty-four hours' abstinence from food, provided 

 that the discharge of nitrogen has been observed for a sufficiently 

 long time previously, and has been so regulated that we can with 

 some degree of certainty assume that there is a deficiency of this 

 readily dischargeable nitrogen in the body. That there would be a 

 considerable discharge of nitrogen there can be no doubt, but the 

 source of it could hardly be the same as in the well- or I might say 

 over-fed body. 



It is, I think, a somewhat extraordinary fact that, on the assump- 

 tion we have made that the nitrogenous value of the diet from 

 February 5th to February 15th was about the same as the expe- 

 rimental diet, with a deficit of 15*16 grams, a further starvation 

 of twenty-four hours should have produced almost identically the 

 same result as a day's starvation, taken haphazard on the day on 

 which I chose to begin an experiment, such as was the case in Expe- 

 riment HE of 1882. I do not wish to invest this fig. 9 with any 

 undue importance ; but it certainly appears to represent some definite 



