The _arrow poison_ of various Indian and savage tribes is a composition of variable and usually unknown nature. It is compounded, for the most part, from vegetable substances, and, if one may judge from the specimens of _curare_ sold by importing houses, their strength is unreliable. While some of these preparations are made by the natives from a species of Strychnos growing in the northern part of South America, this tree is not in universal use for this purpose: in the East Indies they are made from a species of Upas (the deadly Upas of song and story). Some of the poisoned arrows are dipped in putrefying blood. A wound made by these is not necessarily promptly fatal, but would tend to kill by setting up septic disturbance. The vegetable poisons have the property of paralyzing the motor nerves and the circulation to such an extent that death may occur within a few moments after injury. All of these poisons are innocuous when swallowed, and game killed by their agency may be eaten without fear of ill results. Arrow poison of the vegetable variety which is not fatal within a few hours may be recovered from if stimulation be vigorous. Artificial respiration is a factor in keeping such patients alive. IVY POISONING. _In the vegetable kingdom_ there is one kind of plant, the so-called _poison ivy_ (_Rhus toxicodendron_), which is capable of producing intense dermatitis. All persons are not susceptible to this poison--least so those of thick skin and dark hair. It is generally those of blonde type and thin skin who seem most liable to its irritation. The active agent is _toxicodendric acid_, and it is capable of setting up an intense irritation of the eczematous type, with a large amount of hyperemia and edema, especially of soft tissues. When the face is involved the eyelids become puffed so as to make it almost impossible to separate them for purposes of vision. _Ivy poisoning_ is usually contracted by contact with the plant. Symptoms supervene generally within twenty-four hours, and in well-marked cases do not subside for three or four days. The itching is intolerable, and is best combated by strong alkaline solutions or brine. A dilute bromine solution sometimes proves beneficial. Salt and soda in strong solution and vigorous catharsis are also useful. Hypodermic injections may be necessary to induce sleep. Certain species of _sumach_, particularly the genus Cypripedium, may produce similar symptoms, usually less severe. CHAPTER XVII. ACUTE INTOXICATIONS, INCLUDING DELIRIUM TREMENS. DELIRIUM TREMENS.