6 
ON LOBELINA. 
action with litmus paper. This precipitate was suspended in 
water, and a current of hydrosulphuric acid was passed through 
the mixture, until from a green, its previous color, it had as- 
sumed a uniform deep brown hue, when it was gently heated 
and filtered. The brown precipitate was principally sulphuret 
of copper. 
The filtered liquor had an acid reaction, and was evaporat- 
ed carefully to dryness, yielding a dark colored extract. This 
was treated withboilingether,and the ethereal solution allowed 
to evaporate to dryness spontaneously. A mass of a yellow co- 
lor and semi-crystalline texture was obtained which instantly 
turned the blue color of litmus to red when applied to it in a 
damp state. By treating this product with cold ether and eva- 
porating, the acid is obtained purer and in imperfect crystals. 
In this state, lobelic acid, when in solution, is precipitated light 
green by sulphate of copper ; olive brown by persulphate of 
iron ; yellow by acetate of lead ; yellow by baryta water; and 
grayish white by nitrate of mercury. It is not precipitated by 
chloride of barium. 
The action of heat on the active principle of Lobelia in- 
flata. — Six ounces of lobelia seeds, in a bruised state, were 
macerated in twelve fluid ounces of water, acidulated with two 
drachms of acetic acid for three days; the infusion pressed out, 
saturated with magnesia and filtered. This solution had a dark 
greenish color and a very acrid taste. One half of it was put in a 
capsule on a water bath and evaporated to dryness. The ex- 
tract thus obtained was entirely without the acrimony pecu- 
liar to lobelia, and which was so strongly manifested by the 
infusion previous to subjecting it to heat. The other portion 
of the infusion was treated with ether, and the ethereal liquor 
separated and permitted to evaporate. The product had a 
powerful acrid taste and alkaline reaction. 
It was observed that the residue in the retort, after distilling 
water from lobelia seeds, possessed some acrimony; and consid- 
eration suggested the idea, that as the active principle was in 
that case combined with an acid, its presence might exert an 
influence in preserving the lobelina from decomposition. In 
