This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
The fresh rhizome and rootlets of Gelsemium sempervirens, the Yellow Jasmine. From the United States.
Characters.-A very light, fibrous, dirty-yellowish root, with rootlets; odour aromatic and heavy; taste bitterish.
Composition.-Gelsemium contains a powerful alkaloid, gelsemin, gelsemic acid, a volatile oil, and other ingredients. Gelsemin is a colourless, amorphous, odourless, hitter solid, forming salts with acids.
Dose of gelsemin, 1/60 to 1/20 gr.
Gelsemium is a powerful depressant of the motor parts of the cord, causing paralysis, which is followed later by sensory depression and anaesthesia. Respiration fails, and death occurs by asphyxia. The heart is also depressed; the skin is stimulated. The pupil is dilated, and the ocular and levator palpebrae muscles paralysed, all through the third nerve.
Gelsemium has been given in tetanus, asthma, whooping-cough, and other convulsive diseases, with uncertain results. It appears to relieve some cases of neuralgia. In sick headache it may procure great relief, if the dose be pushed.
Non-officinal Preparations. A Fluid Extract; Dose, 2 to 10 min. A Tincture; Dose, 5 to 20 min.