94 Plasma Chlorides and Chloride Excretion 
On a high salt diet consisting of ordinary diet plus from 5 to 
10 gm. of sodium chloride daily continued from 4 to 13 days 
Dogs I and III showed a definite, although in the case of Dog 
III a very slight, increase in the level of the plasma chlorides. 
The study of the blood and urine was made the day following 
the last feeding and last dose of chloride. The urinary excretion 
of chloride was still definitely increased in Dog III but was nor- 
mal in Dog I. Dog II developed a marked diarrhea as soon as 
the chloride high diet was commenced and this probably ac- 
counts for the absence of any increase in the chloride excretion 
and for the very slight degree of change in the plasma chlorides 
the day following the last dose of chloride. 
In Experiment 14, 48 hours were allowed to elapse between the 
last dose of chloride and the study of the blood and urine, and 
this interval proved sufficient to allow a return of the plasma 
chlorides and. chloride excretion to normal, in spite of the fact 
that the dog had received 7.5 gm. of added’sodium chloride daily 
for 20 consecutive days. 
It seems, therefore, that such increases in the plasma chlorides 
and chloride excretion as were observed in “A” group of experi- 
ments 24 hours after the last day of high chloride diet represent 
merely the persistence of the acute disturbance of these factors 
which follow each administration of chloride as shown in the 
“B” group of experiments about to be discussed and which 
may be seen persisting into the following day in Experiment 7, 
““C,.” There is no evidence that the continued use of a high 
chloride diet leads to a permanent or stable increase in the 
plasma chlorides or to an elevation of the chloride threshold. 
The use of a low chloride diet combined with a free flushing 
with distilled water failed to reduce the level of the plasma 
chlorides below normal. In no case were we able to reduce the 
plasma chlorides below the original level observed in that ani- 
mal. The same constancy was observed in the electrical conduc- 
tivity of the serum. These experiments indicate, therefore, that 
in those cases of clinical nephritis, in which following the use of a 
low chloride diet the plasma chlorides fall distinctly below nor- 
mal, this depression of the plasma chlorides is evidence of disease 
and not merely a consequence of the patient’s régime. 
In the “B” group of experiments we studied the immediate 
