292 MATERIA MEDIC A AND THERAPEUTICS. 



gelsemin, gelsemic acid, a volatile oil, and other ingredients. 

 Gelsemin is a colourless, amorphous, odourless, bitter solid, 

 forming salts with acids. 



Dose of gekemin, -fa to -fa gr. 



. ACTION AND USES. 



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. 



APOCYNACE^B. 



Quebracho Bark. (Not Officinal.} The bark 

 of Aspidosperma Quebracho. From Chili. 



Characters. In pieces, f- inch thick ; interior, fibrous and 

 cinnamon-brown, with a short fracture ; exterior, reddish 

 ochre-coloured, warty ; taste, bitter, slightly aromatic, un- 

 pleasant. 



Composition. Quebracho bark and wood contain an 

 alkaloid, aspidospermin, C^H^N-jOa, soluble in spirit, nearly 

 insoluble in water. The wood contains much tannin. 



Non-officinal Preparations. 

 Extract ; Tincture (1 to 5) in doses of 6 min to 1 fl.dr. 



ACTION AND USES. 



Quebracho and aspidospermin reduce the frequency of 

 respiration, through the centre ; the heart's action through 

 the intrinsic ganglia ; the sense of dyspnoea induced by 

 exercise ; and the body temperature. The bark has been 

 used with success in some cases of disease attended by 

 dyspnoea, especially emphysema, but is an uncertain drug, and 

 should be given with caution. 



