REPORT ON A NEW JALAP. 
227 
tating with water the residual liquid of the distillation, by the 
salt water bath, of the alcoholic tincture prepared by mace- 
ration with the powder. At the moment water is added, 
the mixture is whitened as in the case of officinal jalap; 
but after five or six hours, the greater part of the resin hav- 
ing precipitated, the supernatant liquid begins to become clear; 
it is exhibited of a delicate yellow color. In the space of 
twelve hours, this color passes to an apple green, and ulti- 
mately, after several days, to a deep green, there being depo- 
sited upon the sides of a capsule a coating of the same color. 
We have not pushed the examination of this substance further, 
which certainly is not chlorophylle; the phenomena of colo- 
ration resemble, in this respect, but in this only, those of indigo. 
As to the nitrate of potassa, we obtained it by treating with 
cold water, the marc of jalap exhausted by alcohol. The li- 
quor resembling very thick syrup in consistence, was aban- 
doned to spontaneous evaporation in a vessel, the temperature 
of which was maintained at 15° C. At the end of twenty days, 
beautiful prismatic crystals, from five to six lines in length, 
presented themselves upon the surface of the desiccated ex- 
tract; they had all the characters of nitre. 
Two members of the committee undertook the investigation, 
with respect to the medical properties of the Convolvulus 
Orizabensis, upon a certain number of patients in their re- 
spective service at the Hotel Dieu. Here the task of the re- 
porter is rendered simple; in as much as the observations ac- 
corded, without communication between the experimenters, 
it will be sufficient to communicate the results entire to the 
Academy to impart all information necessary upon this 
point. 
The root of the new jalap, reduced to powder under the 
inspection of one of the committee, was administered in thirty- 
three cases, where purgation was indicated. It was given 
thirteen times in the dose of a drachm, sixteen times in the 
dose of half a drachm, and four times in the dose of twenty- 
five grains, always in a cup of vegetable broth. 
Of the patients who took a drachm, four experienced no 
