To detect carb. magnesia, put into a vial a small portion, and add two or three times its bulk of water; after mixing them well, add a small portion of sulphuric acid—effervesence will indicate the presence of a carbonate. On the addition of an {72} excess of acid, the solution should be perfectly clear; whatever is deposited is impurity of some kind; if lime is present an insoluble sulphate is formed.
The presence of moisture is indicated by the magnesia being lumpy, and when shaken, the particles do not flow among themselves easily. Good magnesia has a light, lively appearance, and is pearly white.—(TO BE CONTINUED.)
ON BLISTERING CERATE. BY EUGENE DUPUY, PARMACEUTIST, NEW YORK.
The successful researches of Robiquet in his labors on the Cantharis Vesicatoria, have demonstrated that the cristallisable neutral substance to which he gave the name of Cantharidine, is the proximate epispastic principle of the blistering cerate on which the physician depends in most cases, where an extended and yet deep revulsive action is necessary, whether it is derived from the cantharis vesicatoria or from other members of the trachelid family. The experiments of Mess. Lavini & Sobrero of Turin, have confirmed the supposition made by analogy, of the indentity which exists in the vesicating principle of all these coleopters, and there is a strong presumption that our commerce will soon be enriched with the beautiful cantharis, (C. nutalli,) abounding in the midst of our rising South Western States, and that it will eventually supersede the cantharis vesicatoria we obtain from abroad. If adulteration would not destroy, by its baneful influence, the advantageous form of complex extracts, we could obtain a desirable amelioration of our officinal cerate, by substituting for the powdered cantharides an equivalent proportion of the oleaginous liquid, with which they are saturated in the fresh state, and which is possessed of all the vesicating properties of the insect. That liquid is prepared in various parts of the Sardinian kingdom, especially at Verceil, where it is extensively used by veterinary surgeons in preference to the preparations from the powdered insect, it {73} producing deeper revulsion. It is also used, diluted in bland oleaginous substances for stimulating the activity of feeble serous exudations. As for the present we have not generally access to that natural product of the cantharis, we must select those insects in the best possible conditions, and endeavor to fix their active principle in such a manner as will diminish the liability to spontaneous volatilisation of which it is susceptible, even at ordinary temperature.
I have been for many years in the habit of preparing a blistering plaster which, I think, has some advantages over our officinal cerate, because it fixes the volatilisable principle, and at the same time rather increases than diminishes its energy.
To the officinal plastic mixture in which the powdered cantharides have been gradually incorporated, I add about 5 per cent of a mixture containing equal parts of strong acetic acid (prepared by distillation of the acetates of copper or lead), and pulverised camphor. The acetic acid transforms the cantharidine into an acetate of the same which is not volatilized at ordinary temperatures, and the camphor diminishes the symptoms of strangury which some patients have to endure when the application of a blistering plaster is resorted to. I also usually spread the blister on adhesive plaster on account of the convenient adhesion of that material.
ON THE ADULTERATION OF CERTAIN DRUGS AND THE METHODS OF DETECTING SAID ADULTERATIONS. BY C. TOWNSEND HARRIS, Demonstrator of Chemistry in the New York Medical College.
Since the establishment of the Office of Inspector of drugs in the United States custom houses, a vast amount of spurious and adulterated articles has been prevented from finding its way into our market. By reference to the report of the {74} inspector of drugs for the port of New York, through which is received the great bulk of medicinals imported into this country, some idea may be formed of the enormous quantity of spurious opium, jalap root, scammony, iodine, iodide of potassium, etc. annually introduced from abroad. We find that in ten months, from July 1848 to April 1849, inclusive, 90,000 pounds of adulterated drugs were rejected at the above named office. During the years 1848 and ’50, numerous specimens of adulterated articles were submitted to me for examination by Dr. Baily the inspector of drugs. From a long list I may select one as an instance of the impudence exhibited by foreign manufacturers, in attempting to thrust upon us their villainous compounds, “as standard articles.” I found a specimen of iodine, purporting to be pure, to contain 2 per cent. of non-volatile matter and 40 per cent. of water. The solid materials may be passed over as accidental, but the water is undoubtedly a fraudulent addition.