444 



Mr. S. West and Dr. W. J. Russell. [May 27, 



may therefore be safely regarded as the measure of the total nitrogen, 

 and as forming 90 per cent, of it. 



Note. — An exception to this, of course, is found in the rare cases of 

 acute yellow atrophy of the liver, but even in these cases it is doubtful 

 whether the replacement of the urea by leucin and tyrosin is a con- 

 stant phenomenon. In one case,* which clinically presented the 

 features of acute atrophy of the liver, and in which, post mortem, the 

 liver was found in the condition of acute fatty atrophy, the urea was 

 still normally formed, leucin and tyrosin being absent. 



Table II. — Showing the Percentage of Urea- Nitrogen in the different 



Groups of Cases. 



Pneumonia (6 cases) 90'0 



Jaundice (Case 1) 85' 7 



(Case 2) . 90 '2 



Albuminuria (2 cases) , .................... ^ 86*0 



Collected cases 93 - 8 



Dieted cases , 90*1 



Mean of all. .. 89'3 



Mean, excluding the jaundice and albuminuria cases, 91*3. 



V. " On the Amount of Nitrogen excreted in the Urine by 

 Man at Rest. No. II." By Samuel West, M.B. Qxon., 

 and W. J. Russell, Ph.D., E.R.S. Received May 6, 1880. 



Two methods of investigation have been adopted in inquiries of 

 this kind. The first by stopping the ingestion of nitrogen, either by 

 absolute deprivation of food, i.e., by starvation, or by the giving of 

 non-nitrogenous food. The second by reducing the ordinary diet to 

 the lowest possible limit compatible with health. To the first objec- 

 tion may be made that the experiments are violent, and cannot be 

 long maintained, and that they subject the body to most abnormal con- 

 ditions. Such violence to the ordinary chemistry of the body produces 

 its evidence in the excretions. The nitrogen in the urine under these 

 circumstances varying even more irregularly and widely than under 

 normal conditions, and the short possible duration of the experiments 

 rendering the conclusions drawn, from the small number of observations, 

 unsatisfactory. 



Prom all these objections the second course of investigation is free, 

 no violence is done to the body, and the observations may be prolonged 

 * " Pathol. Soc. Trans.," 1880. 



