A friend informs me that he has found a quantity of woad growing on the Chilterns above the Thame, enough to stain blue a whole tribe of ancient Britons, and also that on a wall by the roadside between Reading and Pangbourne he discovered several plants of the deadly nightshade, or "dwale." This word is said to be derived from Old French deuil, mourning; but its present form looks very English. The only cases of plant poisoning now common among grown-up people are those caused by mistaking fungi for mushrooms, or by making rash experiments in cooking the former, of which Gerard quaintly says: "Beware of licking honey among the thorns, lest the sweetness of the one do not countervail the sharpness and pricking of the other." But with such a list of toxic plants as our flora can show there is always danger from certain species whose properties are quite unknown to ordinary mortals. Are they equally unknown to the herbalists and that mysterious trade-union of country-women and collectors of herbs by the roadside who deal with them? Probably the trade in poisons not used for serious purposes, but for what used in some parts of England to be called "giving a dose," a punishment for unfaithful, unkind, or drunken husbands, still exists as it did some forty years ago. The collectors of medicinal plants cut from the roadside and rubbish heaps, plants whose "operations" for good are quite well known, and have been handed down by tradition for centuries, cannot be absolutely ignorant of the other side of the picture, the toxic properties which other plants, or sometimes even the same plants, contain. Foxglove, for instance, from which digitalis used as a medicine is extracted, is a good example of these kill-or-cure plants. Every portion of the plant is poisonous, leaves, flowers, stalks, and berries. It affects the heart, and though useful in cases in which the pulsations are abnormal, its symptoms when taken by persons in ordinary health are those of heart failure. Thus foxglove is not only a dangerous but a "subtle" poison.
Among other plants which may cause serious mischief, but are seldom suspected, are such harmless-looking flowers as the meadowsweet, herb-paris, the common fool's-parsley, found growing in quantities in the gardens of unlet houses and neglected ground which has been in cultivation, mezereon, columbine, and laburnum. Meadowsweet has the following set against its name: "A few years since two young men went from London to one of the Southern counties on a holiday excursion, on the last day of which they gathered two very large sheafs of meadowsweet to bring home with them. These they placed in their bedroom at the village inn where they had to put up. In the course of the night they were taken violently ill, and the doctor who was called in stated that they were suffering from the poisonous prussic-acid fumes of the meadowsweet flowers, which he said almost overpowered him when he came into the room. The flowers were at once removed, and the young men, treated with suitable restoratives, were by next morning sufficiently recovered to undertake the journey home."  Without knowing what the young men had had for supper, it seems perhaps rather hasty to blame the meadowsweet. But the other flowers mentioned above have a bad record. To take them in order. Herb-paris, which grows in woods and shady places, with four even-sized leaves in a star at the top of the stem, all growing out opposite each other, bears a large, green solitary flower, and a bluish-black berry later. All parts of the plant are poisonous, the berries especially. Fool's-parsley, an unpleasantly smelling, very common plant, which leaves its odour on the hand if the seeds are squeezed or drawn through it, is said to cause numbers of deaths by being mistaken for common parsley and cooked. In the case of poisoning by this plant, it is recommended that milk should be given, the body sponged with vinegar, and mustard poultices put on the sufferer's legs. It is reckoned that one plant produced six thousand and eighty seeds - an unpleasant degree of fecundity for a poisonous weed. Columbine, which is a wild plant with blue or white flowers, as well as a domesticated one, has a toxic principle like that of the monkshood, more especially in the seeds; and the pretty red berries of the mezereon are responsible for the deaths or illness of children nearly every autumn. They are like cherries, and easily picked from the low bushes on which they grow. A dozen are said to be enough to cause death, though this must probably depend on the state of the eater's health. The laburnum, with its golden rain, is potentially a kind of upas tree. The writer has only known of two deaths of children caused by eating the beans in the green pods, but it is said to be a frequent cause of death every year on the Continent, where, possibly, children are less naturally careful about poisonous plants than those in England, to whom risks of this kind are usually and properly made part of the "black list" of the nursery-book of "Don'ts." The seeds will even poison poultry, if they pick them up after they have dropped from the pod. Laburnum is of comparatively recent introduction into Britain, or it would probably earlier have been accorded a place among the severely poisonous plants, dreaded by all.