Q2 Dr. Hamilton on the Jamaica Dogwood. 
dical virtues of the bark or the tincture at least impaired 
by keeping and transportation, and whether the Piscidia is 
an article adapted for supplying the place of the opium of the 
Levant in the pharmaceutical preparations of this country. 
It might also be desirable to institute a set of comparative 
experiments upon the properties of the bark and leaves of 
the young branches, which Jacquin speaks of as being em- 
ployed to intoxicate fish; as well as upon the bark both of 
the roots and branches of the Jacquinia armillaris, and other 
plants employed for a similar purpose. In order to increase 
the utility of these experiments, the substance operated upon 
should be gathered at different seasons of the year, at diffe- 
rent states of the moon, and in different stages of the growth 
of the plant, accurately noting and distinguishing the various 
results. 
It is also of importance to determine, by careful analysis, 
the uniformity or the dissimilarity of the principle upon 
which the medical properties of these various substances de- 
pend, the proportion in which it exists in each, and the 
circumstances under which it is to be found in the greatest 
abundance and highest perfection; as likewise the precau- 
tions requisite for its preservation from decomposition. 
From not being sufficiently alive to all these particulars at 
the time, when a residence upon the spot afforded me an 
opportunity of prosecuting the investigation with success, 
my experiments have been incomplete, and their results un- 
satisfactory. A letter on the subject, which I published in 
Nicholson’s Journal, in October 1812, contains several errors, 
which subsequent experience has enabled me partially to 
correct; and the supply of bark noticed in that letter as sent 
to Mr. Car iste for experiment, having been gathered at an 
improper time (in the month of June), proved inert, as I my- 
self experienced, from having prepared some tincture from a 
portion which I retained for the purpose, was no doubt the 
reason why I never heard from that gentleman on the 
subject. 
As an object equally interesting in a philosophical and a 
medical point of view, and as tending to transfer a most lu- 
erative branch of commerce from Turkey to our own posses- 
sions, the Piscidia Erythryna is well entitled to the attention 
of the Medico-Botanical Society, to whom I now resign its 
further investigation, after having detailed my own imperfect 
experiments, and their result. 
