1880.] Of Nitrogen excreted in the Urine by Man at Rest, 



445 



ad libitum. And here two courses are open, both of which lead in the 

 same direction, though starting from opposite sides. The one which 

 consists in taking, as Playfair and Edward Smith have done, the 

 minimum diets upon which life has been sustained, and estimating in 

 them the amount of nitrogen present. The other in reducing the diet 

 to the lowest possible limit until physiological equilibrium is estab- 

 lished, and then estimating in the urine the amount of nitrogen ex- 

 creted. It is this latter course which we have followed. 



The three cases we have examined were patients suffering from the 

 same affection, viz., aneurism, a disease which produces mechanical 

 rather than constitutional symptoms, and in these cases, so long as the 

 treatment was carried on, produced no symptoms at all, so that for 

 all practical purposes the patients may be regarded as healthy men. 

 They were all placed under the conditions of the most absolute rest, 

 not being allowed to sit up in bed, or even indeed to feed themselves. 

 Their diet was then reduced till it was found that the health was 

 suffering, and then increased until -a condition was reached, which may 

 be called one of " clinical equilibrium," when the health so far as could 

 be determined clinically was perfect. 



The condition of clinical equilibrium being reached, the amount of 

 nitrogen in the food was determined by direct analysis. 



In two of the cases the diet consisted of ten ounces of solids and 

 ten ounces of liquids, distributed as follows : — 



Meat 4 ozs. 



Bread 3 ,, 



Potatoes 2 



Butter 1 ,, 



10 ozs. 



Water 4 ozs, 



Wine 3 „ 



Tea 3 



10 ozs. 



By calculation from Parkes' tables, this should yield 6'3 grms. 

 of nitrogen. Analysis gave a somewhat higher number : in the first 

 determination 7*07, and in the second 6'95. Cf. Tables IV and V. 



In the third case the diet was 8 ozs. of solids and 8 ozs. of liquids, 

 distributed in the same proportion. This by calculation from the pre- 

 ceding analysis should give about 5'6 grms. of nitrogen. 



The analysis of the urine was made in the way described in the pre- 

 ceding paper. The tables give the result of 17 determinations. 



Comparing now the amount of nitrogen ingested in the food, with 

 the amount obtained from the urine, we find (Table V) : — - 



Nitrogen ingested. Nitrogen in urine. 



Case I 7-0 8'6 



„ II 7-0 864 



„ III 5-6 6-4 



