It is a well known fact that when resin of jalap is treated with ether, we obtain two kinds of resin, one soluble, and the other insoluble in ether. Dr. Kayser chose first for his analysis that part of the resin which is insoluble in ether. This resin, purified by means of charcoal, was friable, almost colorless, without smell or taste, insoluble in ether and water, but easily {156} dissolved by spirit of wine; the alcoholic solution reddens litmus slightly. The resin, again precipitated by water, was perfectly soluble in solution of caustic ammonia and acetic acid. This resin was dissolved with difficultly in cold solutions of caustic potash and soda, but was perfectly soluble when hot, and could again be readily precipitated from the alkaline solutions by acids. The solution of this resin, in ammonia was of a bright brown color, and became neutral by volatizing the superfluous ammonia. It is consequently a resinous acid, which is distinguished from other resinous acids, by the facts that it does not precipitate the bases from metalic salts, such as nitrate of silver, sulphate of copper; it afforded only a precipitate when acted upon by basic-acetate of lead. A question arose, whether the resin of jalap, dissolved in alkaline fluids, undergoes any changes in its constitution. To answer this question, Kayser undertook several analyses, the results of which were as follows: The uncombined resin of jalap gave C 42, H 35, O 20.—The resin, precipitated by oxide of lead, gave C 42, H 36, O 21. It is evident that resin of jalap, combined with the bases of salts, acquires the elements of one equivalent of water. Dr. Kayser, has named the unchanged resin of jalap, rhodeoretin, and that modified by bases of salts, hydro-rhodeoretin.
By dissolving rhodeoretin in absolute alcohol and submitting the solution to the action of chlorine, and subsequently adding water to it, Kayser obtained an oily fluid, dark yellow, possessing a pleasant smell, easy to be volatilized by heat, soluble in water, which he called rhodeoretin oil.
The part of the resin soluble in ether, possesses eminently the disagreeable smell of jalap, a prickly taste; its solution reddens litmus, and in drying leaves a greasy spot on paper; it is soluble in alkaline fluids. If the alcoholic solution is allowed to stand, mixed with water, for a lengthened period, prismatic crystalline needles are precipitated. According to these properties, Kayser includes the soluble jalap resin among the fatty acids. Sandrock in general agrees with Kayser; but, according to his analysis, the jalap can be resolved in three {157} different resins, one soluble in ether, the second obtained by precipitating the alcoholic solution by oxides of lead; the third remains unprecipitated in this solution.
That part of the resin which is insoluble in ether, but is precipitated from the alcoholic solution by oxide of lead, Sandrock calls alpha resin; that which is not precipitated, beta resin; that part which is soluble in ether he calls gamma resin.
The alpha resin agrees in its properties with Buchner’s and Herberger’s jalapine. Sandrock calls ipomic acid, the produce of this resin when treated by boiling carbonated alkaline solution; and the one obtained in the same way from beta resin, jalapic acid. The gamma resin forms in ether a yellow solution, and a purple one in concentrated sulphuric acid.—Archiven der Pharmacie.
ON THE PREPARATION OF CHLOROFORM FROM THE ESSENCES OF LEMON, COPAIBA, PEPPERMINT AND BERGAMOTTE. BY M. CHAUTARD, Professor of Chemistry at the Lyceum of Vendome.
M. Chautard, after having completed his experiments for the production of chloroform by means of oil of turpentine instead of alcohol, led by analogy, proceeded to try by a similar method to prepare it by means of the essences of lemon, bergamotte, copaiba and peppermint, and succeeded. However, the quantity of essences upon which he acted was too small to carry on a minute analysis. In the meanwhile, his researches led him to discover formic acid in the calcareous residuum of the operation. It was already known, M. Chautard observes, that oil of turpentine, when old and exposed a long time to the action of the air, was transformed into formic acid, which observations is due to M. Wappen. On the other hand, M. Schneider, by collecting the volatile products of the oxidation {158} of turpentine, by means of nitric acid, detected therein the presence of acetic, metacetic, and butyric acids. Finally, a few years ago, Mr. William Bastick[11] showed that hypo-chlorite of lime, by reacting upon neutral unazotised bodies, such as sugar, starch, &c., gave rise to the formation of a certain quantity of formate of lime; hence, turning to advantage the details given by this chemist, M. Chautard continues—I thus have carried on my operation:—
[11] “Journal de Pharmacie,” 3e serie, 1. 14.
After having ascertained, by means of the solution of indigo, that the residuum contained in the alembic did not contain any hypochlorite of lime, the presence of which would have prevented the extraction of formic acid, I threw the whole upon a cloth, and added sulphuric acid to the filtered liquor to precipitate the lime retained in a state of chloride or formate.—This liquor, after having been filtered anew, was distilled, and the product was a mixture of formic and hydrochloric acids, which I saturated by means of carbonate of soda. By subsequent evaporation to dryness, I succeeded, by adding afterwards a little water, in separating the formate of soda from the chloride. By means of the formate of soda, I proved the principal properties of formic acid, and besides, produced from it the formate of silver, which is decomposed by a boiling heat, leaving a precipitate of metalic silver.