Another rather frequent and most disagreeable accident, which may happen to you when out in the woods, is poisoning by poison ivy. This is due to the leaves or twigs of a plant, which many of you probably know by sight, touching your hands or face. If you do not happen to know what poison ivy looks like, you had better get some one who knows to point out the shrub to you the next time you go into the woods, and then you should try to keep as far away from it as possible. It is sometimes called poison oak, but both these names are incorrect, as the shrub is really a kind of sumac. It takes its different names because it has the curious habit of either climbing like a vine, when it is called "ivy," or growing erect like a bush, or shrub, when it is called "oak." All sorts of absurd stories are told about the leaves of the shrub being so poisonous that it is not safe to go within ten feet of it, when the dew is on it, or to walk past it when the wind is blowing from it toward you. But these are pretty nearly pure superstitions, because it has been found that the substance in the leaves or bark of the shrub which poisons the skin is an oil, which is _non-volatile_, that is to say, will not give off any vapors to the air and, of course, cannot be dissolved in dew or other watery moisture. You must actually touch the leaves in order to be poisoned; but, unfortunately, this is only too easy to do without knowing it when you are scrambling through the woods or hunting for flowers or picking berries. The remedy for poison ivy is a very simple one, and within the reach of anybody, and is as effective as it is simple. This is a thorough scrubbing of the part poisoned, just as soon as it begins to itch, with a nail-brush and soap and hot water. This makes the skin glow for a little while, but it washes out all the burning and irritating oil and, if used promptly, will usually stop the trouble then and there. It is a good idea if you know that you have touched poison ivy, or even if you have been scrambling about actively in woods or patches of brush where you know that the ivy is common, to give your hands a good washing and scrubbing with sand or mud, if there is no soap at hand, in the first stream or pool that you come to. This will usually wash off the oil before it has had time to get through the natural protective coating of the skin.