524 Trans. Acad. Sci. of St. Louis. 
April 8th, traces of the acid were demonstrable two and 
sixteen hours, and none was present in the urine passed 
twenty-four and thirty hours after ingestion. 
The last dose of the salol was taken during a meal consist- 
ing of boiled chicken, farina egg pudding and a glass of dilute 
white wine. The patient was at my office three hours five 
minutes after this meal. As he spoke of experiencing a sen- 
sation of gastric fullness, I expressed the stomach and found 
the contents strongly impregnated with the characteristic 
salol odor. In giving the results of this test, due reservation 
is made for the Souths fallacies pointed out by some observ- 
ers, and admitted by Dr. Ewald himself. 
[Whoever has done any work in the physiologico-chemical 
line, will appreciate the importance of acute discernment 
of different tints and hues, for much of the accuracy in this 
work depends upon the possession of that faculty. For the 
benefit of the inexperienced in that special work, I mention 
the occurrence of an optical phenomenon in connection with 
the salol test. The color of a drop of Ferric chloride solu- 
tion, appears on white filter paper, a greenish-yellow which 
has for its complement “ violet.’? The latter appears very 
quickly on retinal exhaustion for the greenish-yellow. As the 
crucial test for the salicyluric acid, is the appearance of a 
(usually faint) violet color, the possibility of an error is 
obvious. My advice is to either trust to the first quick glance, 
or to repeat the test upon complete disappearance of the nega- 
tive after-image. ] 
© test the absorptive power of my patient’s stomach, I 
followed Penzoldt’s suggestion, i. e. giving 0.1 gram of 
potassium iodide, and timing its appearance in the saliva. 
March 25th it appeared one hour, and one hour and fifteen 
minutes after ingestion. 
March 81st it had not appeared after one hour and thirty 
minutes. 
April 8th it appeared after one hour and fifteen minutes. 
I give these results with some misgivings as my patient’s 
ruminating faculty renders them unreliable; the saliva may 
have been contaminated by regurgitated food particles carry- 
ing with them some of the iodide. 
