Lobelia. Lobelia. The flowering herb of Lobelia inflata, Indian Tobacco; Lin. Syst., Pentandria monogynia; indigenous in the United States. 19

Description. The whole herb is officinal; stem angular; leaves alternate, ovate, toothed; somewhat hairy beneath; capsule ovoid, inflated, ten-ribbed; herb acrid. It is generally found in oblong, compressed cakes.

Prop. & Comp. It has a peculiar odour, and a burning taste, not observed for a short time after the substance has been chewed. Besides colouring matters and the common constituents of plants, it contains a volatile oil or peculiar acid, the lobelic acid, and an alkaline principle, lobelina. This substance forms a yellowish liquid, lighter than water, very soluble in ether and alcohol, and forms crystalline salts with the mineral acids; it is probably the active agent of the plant.

Off, Prep. Tinctura Lobelle. Tincture of Lobelia. (Lobelia, dried and bruised, two ounces and a half; proof spirit, one pint. Prepared by maceration and percolation.) [U. S. Two pints of tincture are obtained by percolation from four troy ounces of powdered Lobelia.]

Tinctura Lobelle AEtherea. Ethereal Tincture of Lobelia. [Not officinal in U. S. P.] (Lobelia, dried and bruised, two ounces and a half; spirit of ether, one pint. Prepared by maceration.)

Therapeutics. In small doses it is expectorant and diaphoretic; in larger, emetic or cathartic. In too large quantities it produces much depression, nausea, cold sweats, and even death, preceded by convulsions; it closely resembles tobacco in its action. It has been much lauded in attacks of spasmodic asthma, and also in other affections of the air-passages, attended with dyspnoea. In some cases it forms a useful adjunct to diuretics.

Dose. Of the tincture or ethereal tincture, 10 min. to 1/2 fl. drm. or more, carefully watching any symptom of vascular depression.