Bodily Labour upon the Discharge of Nitrogen. 465 



The oatmeal was made into thin cakes, the rice cooked in just so 

 mnch water as it would absorb, and eaten with the apples. The 

 potatoes were baked in the usual manner. The sugar and salt used 

 in these experiments were not weighed, but taken to taste. 



The nitrogen in the oatmeal, meat, rice, milk, and cocoa was deter- 

 mined by the soda-lime method ; the nitrogen of the potatoes was 

 calculated from Payen's tables ; they were all grown on one patch of 

 ground on the Rothamsted farm; and were presented to me by 

 Mr. Lawes for the purposes of these experiments. Their composition 

 was probably fairly uniform. 



Nothing excepting the nitrogen was estimated in the food- stuffs, 

 and consequently no comparison can be instituted between the 

 ingesta and egesta except with regard to the nitrogen. 



The nitrogen of the urine was estimated by Liebig's process ; the 

 chlorides by direct titration with argentic nitrate,, with potassium 

 chromate as indicator ; the phosphates by the uranium process, and 

 the sulphates by precipitation with barium nitrate. 



Composition of Urine, Experiment I, 1879. March 5 to March 13. 



Date. 



Quantity. 



Specific 

 gravity. 



Chlorides 

 as NaCl. 



Phosphates 

 a* P 2 5 . 



Sulphates 

 as H 2 S0 4 . 



Nitrogen. 

 Liebig. 



March 5; . 

 „ 6.. 

 » 7.. 

 „ 8.. 

 „ 9.. 

 „ 10 

 „ 11.. 

 „ 12. . 

 „ 13.. 



c:c. 

 895 

 1173 

 1266 

 1433 

 925 

 873 

 980 

 1255 

 1440 



1035 

 1036 

 1031 

 1024 

 1034 

 1032 

 1030 

 1027 

 1027 



13- 97 

 12-45 



11- 46 

 8-95 



12- 14 

 5-81 



12 25 

 12 04 



14- 99 



243 

 4-03 

 291 

 2-52 



2- 16 



3- 14 

 3-14 

 2-78 

 313 



2-78 

 2-69 

 232 

 2-92 

 2-01 

 2-89 

 2-32 

 2-85 

 2-76 



13-80 

 18-26 

 17-39 



16- 50 



17- 09 

 16-80 

 16-16 

 16-99 

 17 31 



Totals . . . 

 Averages . 



10240 

 1137 



1030 



104-06 

 11-56 



26-24 

 291 



23-54 

 2-61 



150 -30 

 16 70 



