92 Plasma Chlorides and Chloride Excretion 
able number of days upon the diet, a period of from 20 to 24 
hours was allowed to elapse after the last feeding and the dog was 
then catheterized and given 100 ce. of distilled water by stomach 
tube to promote diuresis. About 35 minutes later blood was 
taken from the jugular vein for chloride analysis, and about 70 
minutes after the first catheterization the animal was catheterized 
again and the concentration of chlorides in the urine determined. 
The rate of excretion of chlorides was calculated for a 24 hour 
period on the basis of the excretion during the interval between the 
catheterizations. This portion of each experiment is designated 
in the protocols and table by the letter ‘‘A”’ following the number 
of the experiment. The series of “‘A’”’ experiments shows the con- 
dition of the plasma chlorides and of the chloride excretion as a 
result of the continued use of the various diets. The main ob- 
ject of this part of the investigation was to determine whether 
following several days upon a low chloride diet the plasma 
chlorides would be found at a lower level than following a period — 
on ordinary diet, and also to determine whether following a 
series of days on high chloride diet the plasma chlorides would 
be found increased, and if so whether with or without an increased 
rate of chloride excretion in the urine. In order to determine 
whether any injury to the general renal function resulted from 
the high salt diet, blood urea was determined in certain of the 
experiments and the figures were considered as evidence of the 
general renal functional integrity. 
In order to test the immediate effect of a large dose of sodium. 
chloride upon the plasma and upon the chloride excretign a sec- 
ond procedure designated ‘‘B” in the protocols and table was 
carried out in many of the experiments. Immediately upon 
completion of part “A’’ of the experiment 10 gm. of sodium 
chloride in two doses an hour apart were given by stomach tube 
in 5 per cent solution. Immediately after the second dose a 
period of urinary collection was instituted as in “‘A’”’ and blood 
again taken for analysis in the middle of this period. | 
In these experiments can be noted: first, the relation between 
the increase in the plasma chlorides and the increase in the 
chloride excretion resulting from the administration of the sodium 
chloride; second, the effect of the previous dietary régime upon 
this response to the dose of chloride. 
