1867.] Dr. Parkes on the Elimination of Nitrogen. 349 



I draw the conclusion, therefore, that in both these men there was in 

 the first 36 hours a decrease in the amount of urea ; but in the last 12 

 or rest-hours of the 48 hours of the period of exercise, an increase. 



That in the case of S. the total nitrogen was increased throughout the 

 whole period of exercise, the total increase being 1-589 gramme, or 

 24*5 grains of nitrogen, while in the case of T. the total nitrogen, like the 

 urea, was lower in the first 36 hours of the period of exercise, but increased 

 greatly in the last 12 hours. 



It may, indeed, be said that the difference between the amounts in the 

 two periods is after all so inconsiderable as to be explained by the necessary 

 errors of observation. But the constancy of the results in the two men, 

 and in the case of T,, the amount on the first day after the work-period, as 

 given further on, seem to me to show the excess to be real. 



On the same diet the heavier man excreted rather more urea and total 

 nitrogen throughout than the smaller man, except in the first 1 2 hours of the 

 second active day, when the urea was a trifle less. 



The excretion of nitrogen in the urea, as compared with the total 

 nitrogen, was (the ureal nitrogen being taken as unity) as follows : — 



S. T. 



Period of rest 1 to 1*042 1 to 1* 13 



Period of exercise .. 1 to 1'126 1 to ri78 



In both eases there appears to have been a greater relative excretion of the 

 nitrogenous substances other than ureal. Is it not probable that the 

 creatinine was increased ? 



The Phosphoric Acid. 





S. 



T. 



Eest. 



Exercise. 



Kest. 



Exercise. 







1-873 

 •395 

 •749 





1144 

 •5305 

 •3978 



First 12 hours of second period . . 

 Second 12 hours of second period 



•4930 

 •4603 



•5102 

 •4308 





•9533 



1-144 



•9410 



•9283 



On a non-nitrogenous diet the amount of phosphoric acid is not increased 

 in a period of exercise as com.pared with a like period of rest. The imma- 

 terial increase in S. is counterbalanced by as slight a decrease in T. 



The Sulphuric Acid. 





S. 



T. 



Rest. 



Exercise. 



Eest. 



Exercise. 



First 12 hours of second day (day) . . 

 Second 12 hours of second day (night) 



•372 

 •261 



•3791 

 •3084 



•232 

 •195 



-1544 

 •3011 



•633 



•6875 



•427 



•4555 



