Studies on Human Nephritis. 
We have up to the present the reports of nine cases that have 
been investigated for periods of two to ten weeks. 
The patients after admission to the ward, except when an 
immediate change in diet was necessary, were placed on a general 
hospital diet for about three days. The urine and feces were 
collected and analyzed. After this preliminary test the patients 
were placed on a diet composed of two quarts of milk, with enough 
cream and sugar to supply the necessary calories. This diet con- 
tained 12 to 13 grms. of nitrogen, 3 grms. of NaCl and about 1,500 
c.c. of water. A normal individual should reach nitrogenous 
equilibrium on about the third day of its administration. Several 
of our nephritic cases behaved in the following manner: 
Case. 
Duration of 
Period. 
Average Daily N In- 
take ' 'A." 
Average Daily N Output 
in Urine " B." 
B/A Per Cent. 
E.B. 
W.C. 
11 days. 
11 days 
12.5 grm. 
12.5 grm. 
8.89 grm. 
6.91 grm. 
71. 1 
55-3 
The relationship between the eliminated nitrogen to the in- 
gested nitrogen, expressed in percentages we consider an index of 
the kidney's nitrogen eliminative power (N.E.P.) when on this 
standard diet. A minus B minus the amount of nitrogen found 
in the feces, represents the amount of nitrogen retained in the 
system due to the kidney inefficiency. That the nitrogen is not 
retained because of the building up of protein, but because of 
kidney inefficiency, is evident from the fact that iV/S0 3 , ratio 
in the urine of these cases is very low, and corresponds to the 
amount of nitrogen ingested. 
Case M. with quite marked uraemic symptoms eliminated 4.51, 
5.75 and 5.57 grms. of nitrogen per day, with 0.645, 1.113 and 0.97 
grms. of inorganic S0 3 for the respective days. The iV/inorg. S0 3 
ratio during these days was 6.99, 5.17 and 5.72, i. e., the patient 
eliminated about three times the amount of inorganic S0 3 that is 
ordinarily eliminated with the same amount of nitrogen. 
The N.E.P. of our patients E.B. and W.C. was raised very 
considerably after several weeks of a " Protective" diet, i. e., 
a diet containing less nitrogen than the N.E.P. as found in a 
preliminary test. 
The mechanism for the removal by the kidney of one constitu- 
