Chemical Analysis.—From organic mixtures the alkaloid may be obtained by Stas‘s process, and treated according to Vitali with a little fuming nitric acid, and then dried in a water bath: when cold, it must be moistened with a drop of potassæ dissolved in absolute alcohol. A violet colour changing to red is produced, the violet being characteristic, as strychnia when treated as above gives a red colour. The physiological action on the pupil must also be noted. When the berries are taken, the mucous membrane of the stomach may be found dyed of a purple colour, turned green by alkalies and red by acids. Fragments of the berries may also be found in the stomach.
To a small quantity of solid atropine add a drop or two of strong sulphuric acid, then a crystal of sodium nitrite; a yellow colour is produced, which alcoholic solution of potash changes to reddish-violet and then pale rose.
Free atropine gives a red colour with phenolpthalein; the colour is discharged with alcohol, but reappears on evaporating it.
Gerrard‘s Test.—Mercuric chloride dissolved in alcohol gives a red colour.
Blyth‘s Test.—To the solid alkaloid add strong solution of baryta, evaporate, to dryness, and heat the residue, when the smell of hawthorn blossom is given off.
Wormley‘s Test.—An alcoholic solution of bromine gives a crystalline yellow precipitate.
Treatment.—Wash out the stomach and give hypodermic injections of one-third of a grain of pilocarpine, which is the best antidote. Emetics and purgatives, castor-oil and animal charcoal may be administered. The symptoms as they present themselves must be treated on general principles.
N.B.—Belladonna has been stated to act in antagonism to opium, and its administration recommended in poisoning by that drug.
HYOSCYAMUS
Hyoscyamus, Hyoscyamus niger, or henbane (N.O. Solanaceæ), alkaloids hyoscine, hyoscyamine, taken in large doses, produces symptoms not unlike those due to belladonna. There is the same affection of sight—double vision; the same dilatation of the pupils, delirium, confusion of thought, insensibility, and coma. Hyoscine has a hypnotic effect in comparison to the deliriant action of belladonna. But its action varies very much on different people. A form of mania, with wild hallucinations, has sometimes been observed to follow the administration of this drug.