SUMMARY.
Leaves and flowers of the poison ivy plant were extracted with ether and the ether was removed by evaporation. In the residue, the following substances were found and studied: gallic acid, fisetin, the sugar rhamnose, and a poisonous tar, gum, or wax.
The lead compound of the poison was soluble in ether; this fact gave a means of separating the poisonous substance from the non-poisonous matter in one operation.
The poison was not volatile with vapor of acetic acid, or with vapor of alcohol.
The poisonous tar or wax was decomposed by acids and yielded gallic acid, fisetin, and rhamnose, showing the probable source of these compounds in the plant, and indicating that the poison is a complex substance of a glucoside nature.
It was found that a portion of the poisonous substance could be precipitated by lead acetate from a solution of the purified tar in 50 per cent. alcohol.
All cases of poisoning developed on the writer were easily cured with potassium permanganate.
The following method is suggested for obtaining the poisonous substance from the plant: Extract the plant with alcohol, filter, and precipitate at once with lead acetate. Wash the precipitate, dry, and extract with ether in Soxhlet extractors (loosely filled). Combine the ether extracts, mix with water, and pass in hydrogen sulphide. Separate the water and the ether solution, and filter the latter. Wash the ether solution thoroughly by shaking with water, and then evaporate at a low temperature.