Buxine.—This alkaloid is obtained by treating box leaves and stems (Buxus Sempervirens) with diluted sulphuric acid, precipitating the solution by an excess of carbonate of soda or of lime, and then exhausting the precipitate with absolute alcohol. Distil off the alcohol, and dissolve the residue anew in diluted sulphuric acid; again precipitate by carbonate of soda at a temperature of 104° to 122° F.; then pass a current of carbonic acid into the liquor in order to re-dissolve the buxine and precipitate a resin. To the filtered solution of carbonate of buxine add ammonia, and colorless buxine is deposited—Bull. de la Soc. chim. Barbaglia.
Urea—This is satisfactorily determined by M. Marc. Boymond, as follows: The apparatus used has some analogy to the double flask ordinarily employed for the determination of carbonic acid by difference; and the re-agent employed is that of Millon, but much more concentrated; thus, 125 parts of mercury are dissolved in 170 parts of pure, concentrated nitric acid; the solution is first made in the cold, and then completed by elevating the temperature. This solution is diluted by a volume of distilled water equal to its own. The urine or liquid containing the urea is placed in one compartment of the apparatus, the mercurial solution in another, a third compartment contains sulphuric acid to retain the water and the binoxide of nitrogen, and finally the whole apparatus is carefully weighed.
The weight determined, the mercurial solution is allowed to flow into the solution of urea; reaction occurs spontaneously. Gas and aqueous vapor are disengaged, pass through a column of pure and concentrated sulphuric acid, (which retains the water and binoxide of nitrogen, and allows the carbonic acid and nitrogen to pass freely into the atmosphere.) At the close of the operation, in order to terminate the re-action, the apparatus must be gently heated, without however bringing it to the boiling point. Now weigh the apparatus again, and its loss of weight, due to the loss of its carbonic acid and nitrogen, indicates the weight of the urea: 120 parts of the gas correspond to 100 parts of urea. The operation requires about three-quarters of an hour. The weight of the apparatus and its contents, its very great fragility, the difficulty of procuring it at any place, and the necessity for a correct chemical balance, are quite serious obstacles to this method coming into general use; but they take away nothing from its intrinsic value.—Soc. de Pharm. Paris.
The Eclectic Medical Journal, Vol. XXXIV, 1874, was edited by John M. Scudder, M.D.