Appendix. Chemical Analysis of Euphorbia Ipecacuanha.
[This analysis was made by Mr. Cullen, chemist, of this city; a gentleman every way qualified for such investigations. It is extracted from the Thesis of Mr. Roval, a graduate in our University.]
Four drachms of powdered Euphorbia were digested in four ounces of Alcohol, specific gravity 827, for the space of ninety-six hours, half of which time it was exposed to a heat between ninety and a hundred degrees of Farenheit's thermometer. At the expiration of this time, the alcohol had acquired a pale lemon colour, which disappeared on the addition of a few drops of nitric acid, without producing any other phenomenon than the evolution of a peculiar etherial odour. On the addition of water, slight fioculi appeared, so minute as to elude chemical examination; they were redissolved of the addition of alcohol. To another portion of this alcoholic solution, tincture of galls was added, with no other effect than changing its colour to a dark brown. A separate portion was tested by a solution of gelatine, which produced no change whatever in its sensible or chemical properties. The non-existence of cinchonin or tannin, being thus ascertained, the remaining tincture was submitted to distillation in an alembic, placed in a water-bath, saturated with muriate of soda. On the application of heat there ascended a small quantity of pure alcohol. On an elevation of temperature, there came over a dark brown fluid, bearing a striking analogy in smell and colour, to highly rectified oil of amber; the residuum, when hot, was of the consistence of tar; but on cooling, assumed a concrete form, extremely brittle, and when broken, of a glassy fracture, not unlike kino.
A small quantity of this extract was subjected to distillation, and afforded carburetted hydrogen and carbonic acid. On another portion of the extract, distilled water was boiled until it formed a brown turbid mixture, which deposited, on cooling, small shining molecules, that resisted the successive action of highly concentrated ether and alcohol; but were converted into oxalic acid on the affusion of nitric acid.
There resides, therefore, in the Euphorbia Ipecacuanha, a colouring principle, soluble in alcohol, and insoluble in water; forming with nitric acid oxalic acid, and a peculiar odorant principle.
That it contains resin, may be concluded from water precipitating the alcoholic solution, and alcohol redissolving the precipitate; and, from the quantity of carburetted hydrogen it evolves when heated, that its emetic matter differs from that found in the Callicocca Ipecacuanha, by the French chemists (Messrs. Pelletier and Magendie), may be inferred by its not forming a precipitate with the gallic acid, which the other does abundantly, nor is its emetic principle as soluble in acetic acid, as that of the Callicocca ipecacuanha.
To ascertain further its constituent principles, the following experiments were instituted: Four ounces of Euphorbia, finely powdered, were infused in six ounces of distilled vinegar, specific gravity 1300.5, water taken at 1000; in 72 hours the vinegar had acquired an increase of fifteen grains in specific gravity, and a light straw colour, which remained permanent notwithstanding nitric acid had been poured on it. To be certain that no mistake had been committed in weighing the vinegar, the residuum, insoluble in acetous acid, was carefully dried; when its loss was found to be in exact ratio to the increased specific gravity of the solution.
All the experiments performed on the alcoholic solution were repeated, and attended with similar results, except that a quantity of mucilage was precipitated by the super acetate of lead.
In another experiment six drachms of Euphorbia coarsely powdered were infused in eight ounces of distilled water for the space of two days, and afterwards boiled for four hours; the decoction was mucilaginous, and of a light brown colour, possessing an odour resembling oat-meal. It afforded similar products with the preceding; and w T as not precipitated or altered in appearance by a solution of tartar emetic, nitrate of potash, or a watry solution of opium.
Iodine produced a copious blue precipitate; thereby indicating the presence of starch, which precipitate was collected on the filter, in the form of Ioduret of starch.
Vegetable Materia Medica of the U.S. or Medical Botany, 1817 (Vol. I), 1818 (Vol. II), was written by William P. C. Barton, M. D.