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SELECTED ARTICLES. 
served. But do they not render it highly probable, that were 
it not for the injurious effects of drying, this plant might be 
much more active, much less liable to disappoint the practi- 
tioner than it is well known to be, and, perhaps, universal 
in its control over all constitutions? 
Several more direct evidences may be adduced in support 
of the opinion that the powers of the growing plant are differ- 
ent from those of the dried leaves. When first taken from the 
ground, the leaves are strong, erect, and vigorous; in a short 
time, an hour is sufficient, they become collapsed and limber, 
lose their firmness, grow flaccid and droop. This is the first 
symptom of change. If an adequate heat be now applied, the 
smell of the plant is extensively diffused throughout the apart- 
ment, which proves the dissipation and loss of some ingre- 
dient of the leaves, probably the volatile oil. The brilliant 
green color on the surface is also changed for a dusky olive. 
It is not easy to conceive, that such striking changes in the 
physical constitution of the plant can take place without some 
modification of medicinal power. But if to these sources of 
change, we add that arising from the very bad mode of dry- 
ing which the Pharmacopoeias inculculate, it can scarcely be 
considered doubtful, that much injury is sustained. The 
Dublin Pharmacopoeia directs the herb to be enclosed in 
paper bags, exposed to 90° or 100° for an hour, and then 
dried on a wire gauze. The London Pharmacopoeia orders 
the leaves to be lightly stewed and hastily dried by a gentle 
heat. The Edinburgh Pharmacopoeia merely desires, that 
such small quantities as can be hastily dried, shall be exposed 
to the moderate heat of a fire hearth; and adds the following 
test: " sienim eorum vires optime servantur, cujus indicium 
est color nativus quam perfectissime constans." 
This preservation of the green color is universally admitted 
as the test of good drying; and when the green color is des- 
troyed, it is conceived that the medicinal efficacy of the sub- 
ject is not to be relied on. It is a convenient test, for without 
it we should in every case have recourse for proof to the 
actual exhibition of the medicine. 
