422 Botanical Society of Edinburgh. 
The druggists here, dissatisfied with this English bark, have got 
the officinal substance imported from America. It is now brought _ 
in 1 Ib. packages, as made up in America; is in small fragments not 
more than an inch long, is free from epidermis, and otherwise corre- 
sponds with Wood and Bache’s description. 
Dr. Maclagan made various experiments with different samples of 
the English bark, to determine whether or not it would yield any 
hydrocyanic acid ; but though he subjected four separate portions to 
distillation, he could not obtain from it the least trace of this active 
principle. It is obvious, therefore, that the bark of English growth 
wants one of the most important constituents of the American bark, 
and is comparatively of little value. Dr. Maclagan’s trials of it in 
practice had not tended to raise it in his estimation. It did not ap- 
pear to have any special advantage over other bitters of which there 
are plenty, and from the great quantity of altered tannin and extractive 
which is taken up in the infusion, it even appeared frequently to 
disagree with the stomach. From the American imported bark, 
however, Dr. Maclagan separated hydrocyanic acid in small quantity 
by distillation. It made a very bitter infusion, and deposited some 
tannin on cooling. Alcohol appears to take up more of the bitter, 
and water more of the astringent matters of these barks. Even the 
American bark, however, which is now in the best shops substituted 
for the English, does not appear to possess that combination of 
sedative and calmative action with tonic power, for which it is pre- 
ferred in the United States, and did not appear to be so useful, and 
cannot be so uniform in quality, as a combination of some of our 
common bitters, such as colombo with hydrocyanie acid, a form of 
prescription which had proved very efficacious in his hands. In fact 
the want of calmative property had led to its being generally prescribed 
with hydrocyanie acid added to it, and thus it did not appear to 
Dr. Maclagan to have any special advantages. 
The fact that the bark of the C. serotina yields hydrocyanated oil 
has been established by the experiments of Procter quoted above ; 
that the bark of C. Padus yields hydrocyanic acid also has been long 
known. Dr. Maclagan had made some experiments with the fresh 
twigs of C. Virginiana from the Botanic Garden of Edinburgh, and 
found that it yielded hardly any volatile oil, not enough to render 
the distilled product milky, but it gave a certain amount of hydro- 
eyanic acid. 
From two ounces of fresh bark distilled with water, he obtained a 
distillate which gave 0:08 of real hydrocyanic acid ; but the decoction 
contained little tannin, was barely bitter, and had rather a sweetish 
taste. It was obvious, therefore, that the bark. of the shrubby C. 
Virginiana would be of little use as a medicine. 
Dr. Maclagan likewise examined the bark of C. Padus. From 
two ounces of the fresh bark he got by distillation a fluid which had 
a distinct layer of oil on the surface, and contained 0°26 of real hy- 
drocyanic acid, or more than three times the amount got from C€. 
Virginiana. The decoction of C. Padus also was richer in tannin, 
and was strongly and agreeably bitter. Dr. Maclagan had not had 
