358 Dr. Parkes — Further Experiments on the [Mar. 2, 



Nitrogen by soda-lime. 





8 A.M. 



to 



8 P.M. 



8 P.M. 



to 



8 A.M. 



Total in 

 24 hours. 



Total nitrogen 

 calculated 

 from urea. 





2 "45 1 

 4'997 



1-361 

 3-268 



5-936 

 5'4 2 7 

 4-328 

 3-812 

 8-265 



6*ioo 

 5*008 

 4'3*7 

 3-4i8 

 7-465 



The effect of the previous small entry of nitrogenous food is clearly seen ; 

 on the 1st day the nitrogen fell almost to the amount of the 2nd day in 

 the previous experiments. On the 3rd day, on the contrary, it was greater 

 than on the corresponding day of the former series. 



The amount of nitrogen was actually greater on the 5th day than on the 

 1st. Except the excessive exercise of the 4th day, no other obvious cause 

 existed for this elimination on the 5th day. No mistake seems possible ; 

 for the urinary water on the 5th day was less in quantity than on the 1st, 

 2nd, and 3rd days, while the nitrogen was 2 grammes more than even on 

 the 1st day after nitrogenous food was left off. An error in analysis is not 

 possible, since not only were the analyses repeated, but the process by urea 

 gave results corresponding to that by soda-lime. No constitutional condi- 

 tion which could cause excess in elimination was indicated either by the 

 pulse or body temperature, and the man felt perfectly well. I need hardly 

 say that no nitrogenous food was taken ; for it is quite certain that it was 

 not. 



The increase in the 5th day in the 1st series, though less marked, is still 

 unequivocal, and there seems therefore no rashness in stating that the con- 

 clusion of the experiments formerly laid before the Society is affirmed, viz. 

 that severe exercise causes an increase in the elimination of nitrogen in the 

 period of rest after the exercise. It is noticeable that in this man the 

 increased elimination was not in the hours immediately succeeding, but on 

 the following day, and lasted for some time. 



Whether during the period of exercise the nitrogen was lessened is not 

 so clear, as the fall from 4*328 grammes on the 3rd day to 3 - 812 on the 

 4 th or exercise day might be merely the continuing effect of the depriva- 

 tion of nitrogen. The experiments formerly recorded seem to me better 

 adapted to determine this point, which, however, certainly requires more 

 evidence in confirmation before it can be accepted. 



That changes go on in the muscles during exercise which lead to an 

 increase in the outflow of nitrogen afterwards must, I think, be admitted ; 

 and on this point it seems that the statement of Liebig must be supported 

 against Voit. 



It may be interesting to give the mean pulse and temperature during 

 these days of non-nitrogenous feeding for comparison with the normal. 



