All parts of the plant contain the toxic alkaloids, but in unequal degree. The total quantity of the alkaloids is largest in the roots (0·4 to 1 per cent.), which in the fresh state contain no Atropine, but only Hyoscyamine; the leaves and fruits contain less of the alkaloids, and cultivated plants have been found to be poorer (0·26 per cent.) than wild (0·4 per cent). The root has been found to be five times as toxic as the berries. Drying does not destroy the poisonous properties.
Symptoms. In quantities which are not fatal the symptoms are nausea, dilatation of pupils, muscular weakness, stumbling, falling, and rising only to fall again. These are followed by vertigo, frenzy, and coma (more rarely). There is a slight slackening in respiration, and an increase in the rapidity of the heart’s action. Dysury and constipation are observed.
In fatal quantities the symptoms are more intense and make their appearance more rapidly. The nausea is accompanied by vomiting, and there is almost complete loss of sight. Sensitiveness is at first increased but later diminishes and gradually disappears; complete incoordination of movements; increase in the heart’s action but a gradually weakening pulse; stertorous, painful respiration; decrease in temperature. There is repeated urination at the commencement of the poisoning, and then dysury. At the approach of death there are muscular trembling and clonic contractions. This phase of convulsions is short but very clear in some cases: other cases do not leave the deep coma in which they are plunged (Cornevin).
In regard to cattle, the following symptoms are given by Müller: Injury to sight, dilatation of pupils, constipation, later bloody evacuations, pain in hind limbs, rapid pulse, difficult breathing, restlessness, frenzy and finally paralysis.
REFERENCES.
[4], [16], [61], [73], [81], [128], [138], [143], [151], [157], [161], [190], [205].
CHAPTER V
SCROPHULARINEÆ
Foxglove (Digitalis purpurea L.). The Foxglove has been recognized as poisonous for centuries, and one of its trivial names is Dead Men’s Bells—a name suggestive of the consequences of taking it. It is the source of the well-known drug; and cases of human poisoning have been very common, though by no means always fatal—indeed, Esser says “seldom resulting in death.” Animals are not known to touch this plant, but it may possibly be included in rough meadow hay, though only one case, in which two cows and a horse became ill after eating hay containing dry foxgloves, has come to notice (Veterinary Record, 1906). Cornevin, however, experimented on animals, and found the following amounts of fresh leaves capable of causing death in the animals specified:—
| Horse | 120–140 | grammes | (4 to 5 oz.) |
| Ox | 160–180 | „ | (5·5 to 6·5 oz.) |
| Sheep | 25– 30 | „ | (0·88 to 1 oz.) |
| Pig | 15– 20 | „ | (0·5 to 0·7 oz.) |
The weight of dried leaves would be only one-fourth of these figures.