204 
Selected Articles. 
opinion upon this point; and so far as this goes, is in decided 
opposition to the hypothesis, that the active principle of this 
species is the same as of the European — that, as has been 
before observed, being hydrogogue cathartic, while this pos- 
sesses no cathartic powers. It has been suggested, that this 
diversity in medicinal effects might be explained on the sup- 
position that veratrine, though the proximate active principle 
did not exist in the plant in the form of a bi-gallate, as in the 
European species — the diversity in medicinal properties war- 
ranting the belief that the salt was different, though the base 
might be the same. This opinion, though at first view plau- 
sible, is neither supported by analogy, nor in accordance with 
the known laws of vegetable chemistry. Although solubility 
and activity are often affected by a change of acid simply, I 
have no knowledge that vegetable chemistry furnishes us with 
any instance of a change in the medicinal properties of the 
proximate active principles of a plant, by varying the acid 
with which the proximate principles or base may be combined. 
Among many instances which may be adduced where this 
integrity in medicinal effect is preserved in spite of a change 
of acid, the sulphate and acetate of quinine, sulphate and tar- 
trate of sanguinarine, sulphate and acetate of morphine, are 
familiar examples. I have been thus particular on this point, 
as the general impression of identity in active principle with 
the European species has greatly interfered with the investi- 
gation this plant deserves, and would otherwise have received. 
Since the above was written, T have endeavoured to test 
the correctness of my conclusions by chemical analysis. Al- 
though my experiments were not sufficiently extensive to ac- 
complish this object, still I would briefly detail the process 
adopted. The preparation from which I attempted to obtain 
the proximate active principle was the infusion, prepared by 
adding boiling water to the finely bruised root, and allowing 
it to macerate twenty-four hours, the quantity of root being 
such as to saturate the water. After filtering this infusion, a 
precipitate of a dull white colour was thrown down by am- 
monia. This precipitate, after being repeatedly washed, was 
