J. H. Austin and L. Jonas 93 
In two instances on the day following the administration of the 
10 gm. of sodium chloride just described a third period of urinary 
collection with collection of blood was carried out to determine 
whether any effect of the large dose of chloride still persisted 24 
hours later, either in the plasma or in the rate of chloride excretion. 
This part of the experiment is designated in the protocols and 
table as ‘‘C.” | 
In Experiment 4, Dog I, the effect of a mild uranium nephritis 
in an animal on a medium chloride diet was studied for compari- 
son with the effect of high salt feeding. 
Methods. 
Urine.—The chlorides were estimated by the Volhard-Harvey method 
(3). The concentration is indicated in the protocols and table as gm. of 
sodium chloride per liter of urine under ‘‘E.’’ The rate of chloride ex- 
cretion is expressed as gm. of sodium per 24 hours, calculated from the 
excretion in the number of minutes of urinary collection employed in each 
experiment; this rate of excretion is given in the protocols and table 
Hocus 
Blood.—Blood was drawn from the jugular vein directly into a centri- 
fuge tube containing potassium oxalate crystals beneath paraffin oil, 
centrifuged immediately, and the plasma pipetted from the cells (4). In 
the plasma so obtained chlorides were estimated by the method of McLean 
and Van Slyke (5). The figures are given under ‘“‘N’’ as gm. of sodium 
chloride per liter of plasma. 
Blood urea nitrogen was estimated on the whole blood by the method 
of Van Slyke and Cullen (6). The figures given are mg. of blood urea 
nitrogen per 100 cc. of blood. In some of the experiments blood was also 
drawn from the vein, allowed to clot, centrifuged, and the serum used 
for the estimation of electrical conductivity. Decinormal potassium 
chloride solution was used as a standard and determinations were made 
at 25°C. The specific conductivity is given under ‘‘X.”’ 
In all analyses duplicate determinations were made. 
RESULTS. 
The results of the fourteen experiments on the three dogs are 
given in the table.. The detailed protocols are appended. 
It will be noted that on the same ordinary régime the three dogs 
differed somewhat in the level of plasma chlorides; Dog I showing 
the highest, 6.3 gm. per liter, and Dog II the lowest, 5.9 gm. 
The chloride excretion in all three was small. 
