74 



Scientific Proceedings (64). 



water balance. There are practical and theoretical objections to 

 such studies. Constant diets are impracticable at Bellevue at 

 present and there are too few workers to carry out such investiga- 

 tions on a large scale. On the theoretical side, we know that a 

 diminished rate of elimination of water and chlorides does not 

 necessarily indicate renal insufficiency but may occur in cardiac 

 decompensation with edema. 



A diminished rate of elimination must eventually lead to reten- 

 tion and the most accessible place to look for retention is in the 

 blood serum. A complete chemical examination of the serum 

 should reveal the retention of certain substances but in the case 

 of NaCl we know that retention of NaCl and water occur together 

 so that the concentration of NaCl in the serum remains practically 

 constant. 



In an attempt to overcome these theoretical and practical 

 difficulties we have worked out a system of physical analysis of 

 the blood serum which has yielded valuable information as to the 

 relative concentration of chemical substances possessing similar 

 physical properties. The freezing point, the refractive index, and 

 the specific gravity of the blood serum are independent variables 



Table. 





Total Averages. 



Extremes. 



F. P. 



AiVd X 10'. 



;sp. g. 



F. 



P. 



HN d X io«. 



Sp. g. 





0-57 



17.4 



1.026 



0.55- 



-0.59 



16. 7-18.0 



1. 025-1. 027 



Cardiacs with edema 

















(13) 



0.56 



I7.I 



1.025 



0-53- 



-O.58 



IS-3-I9-2 



1. 024-1. 030 



Nephritics with edema 

















(20) 



O.S6 



I3S 



1.020 



0-53- 



-0.59 



n.i-15-7 



1.015-1.023 



Nephritics with uremia 

















(6) 



O.67 



18. 1 



1.029 



0.76- 



-0.61 



18.9-16.5 



1. 030-1. 027 



Nephritics with uremia 

















and edema (3) . . . . 



O.62 



I4'3 



1.022 



O.63- 



-0.61 



13.2-15.4 



1. 020-1. 025 



Arterio-sclerotics with 

















hypertension (3) . . 



o.S7 



20.4 



1.031 



0-59- 



-0.57 



20.8-19.7 



1.033-1.030 



within certain limits. Systematic use of these methods on 50 

 cases, chiefly nephritics, cardiacs, and arterio-sclerotics, has 

 shown that definite serum pictures exist which are more or less 

 characteristic of different types of nephritic or cardiac disease. 

 Nephritic edema is associated with hydremia while in cardiac 

 edema the blood serum is normal. Uremia may or may not be 



