[Illustration: FIG. 14.—Drawings, about half the natural size, of the leaves of the common quinquefoliate Virginian creeper (1 and 2), of the adherent “Ampelopsis Veitchii” (3 and 4), and of the poison-vine, _Rhus toxicodendron_ (5 and 6). From specimens in the Botanical Department of the Natural History Museum. Note especially the greater length of the stalk of the central leaflet in the poison-vine. Note also that the common Virginian creeper has sometimes only three leaflets (2) instead of five, and that “Veitchii” has either three leaflets, as in 3, or has the leaflets united into one three-pointed leaf, as in 4.] The poison of the poison-vine only acts upon a limited number of individuals, many people being perfectly immune. At the same time, the effect upon susceptible people appears to be enhanced with every fresh attack; even after the total removal of the poison-vine and its dust from proximity to a susceptible person, he or she is apt for some time—owing to the retention of some trace of the oil in the skin or clothes—to have slight attacks. According to a writer who two years ago gave in the _Spectator_ an account of his own case, the first symptom of an attack is almost invariably a redness and irritation of the eyelids, accompanied by shivering. In a few hours the eyelids are closed, the features unrecognisable, and the skin covered with little blisters. Then the lips swell enormously, the glands of the neck also. In four days the arms and hands are reached, each finger appearing as if terribly scalded and requiring separate bandaging. Then sometimes the lower limbs are involved. After ten days the attack passes off, leaving the patient in a pitiable state of weakness to grow a new skin and recover from other painful results of the poisoning. But no immunity is conferred by an attack; the unhappy victim (who is ignorant of the cause of his sufferings) may, and frequently does, get a new dose of the poison as soon as he has recovered, and the whole course of the illness has again to be passed through. If this account should fall into the hands of any one who is being unwittingly poisoned by the American poison-vine, and may therefore be saved by what I have written from further suffering, I shall be greatly pleased.