From the Manufacturer:
Expectorant, diaphoretic, anti-asthmatic. It should not be employed as an emetic. (Herbalists, who use lobelia far more than the ordinary practitioners, nearly always prescribe it in doses large enough to prove emetic, and regard it as of greater value thus used. - EDITOR.) Some authorities attach great value to it as an expectorant in bronchitis, others as a valuable counterirritant when combined with other ingredients in ointment form. It is sometimes given in convulsive and inflammatory disorders such as epilepsy, tetanus, diphtheria and tonsilitis. There is also difference of opinion with regard to its narcotic properties. Where relaxation of the system is required, as, for instance, to subdue spasm, Lobelia is invaluable. Relaxation can be counteracted by the stimulating and tonic infusion of capsicum. It may be used as an enema.
Externally, an infusion has been found useful in ophthalmia, and the tincture can be used as a local application for sprains, bruises, or skin diseases, alone, or in powder combined with an equal part of slippery elm bark and weak lye-water in a poultice. The oil of Lobelia is valuable in tetanus. One drop of oil triturated with one scruple of sugar, and divided into from 6 to 12 doses, is useful as an expectorant, nauseant, sedative, and diaphoretic, when given every one or two hours.