Henbane (Hyoscyamus niger L.). The poisonous character of Henbane is well known, but the plant is by no means common (except in Ireland), though found in parts of England, Scotland, and Wales. Poisoning of live stock may occasionally occur, but the disagreeable odour is likely to prevent all but abnormal or very hungry animals from touching it. The seeds are eaten by birds, apparently without injury, but poisoned chickens which ate the ripe seeds in Montana. Cornevin records that cows have been poisoned by eating the plant when given mixed with other herbage. There are numbers of cases of children having been poisoned by eating the seeds. The root has also caused accidents by being taken for other herbs, and the young shoots and leaves have been used in error as a vegetable. A case was reported in the press in 1910 in which 25 men and women visitors at a Davos pension suffered from the effects of eating the root of Henbane given in error for horse-radish, or mixed with it. All suffered from strange hallucinations, but with prompt and careful treatment all had recovered in twelve hours. Kanngiesser says that poisoning by this plant very seldom terminates fatally.
Welsby records a case in which animals were poisoned in a field in which Henbane was grown for medicinal use some years before (Veterinary Record, 1903). According to Rodet and Baillet (vide Cornevin) small quantities of the seeds are in some countries mixed with the food of fattening stock; if true that fattening is promoted, it is probably due to the inducement to quiet and repose caused by the narcotic properties of the seeds.
Toxic Principle. Poisoning by Henbane is due to the alkaloids Hyoscyamine (C17H23NO3) and the closely related Hyoscine, or Scopolamine (C17H21O4N). The glucoside Hyoscypicrin is also found in Henbane. The poisonous property is not eradicated by drying or boiling. The leaves of Henbane grown in Europe contain from 0·04 to 0·08 per cent. of total alkaloid, and the seeds 0·06 to 0·10 per cent. (Bul. Imp. Inst., 1911).
Symptoms. Henbane is an anodyne, and hypnotic. The symptoms resemble those caused by Atropa Belladonna (p. [58]). The important differences (Cornevin) are that there is here abundant salivation and no dryness of the mouth as in Atropa. There is dilatation of the pupils; and mydriasis, which is dissipated more slowly than in Belladonna poisoning.
Further differences in the action of the two poisons are given by Winslow (via Pammel): The tetanic stage succeeding spinal paralysis observed in Atropine poisoning does not ensue with Hyoscine. The latter alkaloid slightly depresses and slows the heart and does not paralyse the vagus terminations, nor depress the motor and sensory nerves or muscles. The circulation is but slightly influenced, and vasomotor depression only occurs in the later stage of lethal poisoning. Death occurs from paralysis of the respiratory centres. Poisoning in animals is exhibited by loss of muscular power, slowing and failure of respiration, stupor, and asphyxia. The pulse may be infrequent, the pupils are dilated, and the skin is moist rather than dry.
The following symptoms in animals are given by Welsby: Nervo-muscular exaltation, eyelids and irides much dilated, eyes amaurotic and very bright, pulse full, temperature normal, respiration difficult and hurried, profuse salivation, muscles of neck and extremities in a state of tetanic rigidity, considerable abdominal distension, stercoraceous and renal emunctories entirely suspended, death.
In a cow there was observed, two hours after eating, dilatation of pupils, the conjunctivæ were injected, and the carotids beat violently. There were general convulsions, loud respiration, salivation, and purgation. According to Pott the milk of affected cows is of an unpleasant taste.
REFERENCES.
[4], [16], [39], [57], [68], [73], [81], [128], [141], [151], [157], [161], [190], [203], [205], [213], [257].
Garden Nightshade (Solanum nigrum L.). This species is described as “one of the widest spread weeds over every part of the globe, except the extreme north and south; varying so much in warmer regions as to have been described under more than forty names” (Bentham and Hooker). In the same way there can be no doubt that, though it must always be regarded as poisonous, this plant varies considerably in toxicity according to soil, climate, and general condition of growth. For this reason the plant may sometimes be eaten in considerable quantities without ill effects, while in other cases it will undoubtedly prove poisonous.