[5] Oil of lavender is a pleasant means of local protection against mosquitoes, etc. Oil of tar is also in common use. A mixture of equal parts of camphor and chloral, with menthol dissolved in the mixture (camphor and chloral when mixed without other ingredients quickly form a dense fluid like glycerin), gives great local relief from the itching and pain of insect bites.
Many of the lower forms of marine animals are capable of inflicting stings by their rays, or minute injuries in other ways, which give rise to great temporary annoyance. The stinging nettle, etc., is an instance of this kind. The lesions produced in this way partake of the nature of a more or less acute dermatitis.
ARROW POISON.
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.