Effects of Rhus Tox. on the Skin

The toxic action of this species is one difficult to explain. The first noticeable peculiarity is its choice of victims, .many persons being entirely devoid of response to its influences, many others peculiarly susceptible.

Another peculiarity is that in many cases it is not necessary to even touch the plant to be severely poisoned.

A third pecularity is that the plant is more poisonous during the night, or at any time in June and July when the sun is not shining upon it. Absence of sunlight, together with dampness, seems to favour the exhalation of the volatile principle (Toxicodendric acid) contained in the leaves. An acrimonious vapor, combined with carburetted hydrogen, exhales from a growing plant of the poison ivy during the night. It can be collected in a jar, and is capable of inflaming and blistering the skin of persons of excitable constitution who plunge their arms into it.