52 Dr. Parkes on the BUmination of Nitrogen. [June 20, 



increased excretion of nitrogen was, I believe, not at all connected with 

 it. Thus in the first and third periods the nitrogen was almost the 

 same, yet in S. the difference in the mean amount of water was 266 cub. 

 centims., and in B. was 60 cub. centims. In S., in the fifth period, the 

 amount of water was the same (within 6 cub. centims.) as in the first 

 period, yet the nitrogen was more than 3 grammes in excess. If indi- 

 vidual days are taken, no obvious relation appears between the urinary 

 water and the nitrogen. The largest amount of water in S. (17 60 cub. 

 centims.) corresponded to 19'536 nitrogen, while the largest amount of 

 nitrogen (23-488) corresponded to 1430 cub. centims., and the next 

 amount of nitrogen (21'25) was passed in only 900 cub. centims. of 

 urine. In B. the largest amount of nitrogen (21'597) was contained in 

 the largest amount of water (1610 cub. centims.), but almost as great 

 an amount was contained in 1000 and 920 cub. centims. So that dif- 

 ferences in the amount of water cannot explain the variations in the exit 

 of nitrogen. If not owing to alteration in food, nor to variable passage 

 of water through the kidneys, it seems tolerably certain that the condi- 

 tions of rest and exercise were the causes of the variation. 



JEoccretion of Nitrogen hy tlie hoioels. 



The two men did not have quite the same amount of intestinal excreta. 

 The average daily weight (sixteen days) in the case of S. was 4" 798 

 ounces avoirdupois or 136 grammes ; while in the case of B. they 

 amounted only to 3'97 ounces, or 112'8 grammes.^ 



The exact daily weights are given further on, and I will now merely 

 state the amount of nitrogen, which was determined three times. 





Nitrogen in grammes. 



S. 



B. 





1*227 



1- 486 



2- 138 



0*644 

 1*091 

 1-504 



Mean 



1*617 



1*079 



B. passed (if these three days represent the mean) 0*538 gramme less 

 nitrogen daily by the bowels than S., and during the first twelve days he 

 passed on an average 0*6 gramme more nitrogen in the urine, so that 

 during these twelve days the discharge of nitrogen by the conjoint 

 channels was within 1 gramme the same in the two men ; the amounts 

 being in S. 238*848, and in B. 239*757 grammes in twelve days, while 

 the amount of nitrogen passing in (independent of a small amount in 

 the tea, coff'ee, butter, &c.) was 235*32 grammes. This accordant result 

 proves, I believe, both the estimate of the nitrogen in the food and the 

 collection and analysis of the excreta to have been accurate. I was 



