"Boil, for half an hour, six pounds of coarsely powdered Chinese rhubarb in six gallons of water, acidulated with two and a half fluid ounces of sulphuric acid; strain the decoction, and submit the residue to a second ebullition in a like quantity of acidulated water; strain as before, and submit it again to a third ebullition. Unite the three decoctions, and add, by small portions, recently powdered pure lime, constantly stirring it to facilitate its action on the acid decoction. When the decoction becomes slightly alkaline, it deposites a red flocculent precipitate, and the fluid is changed from a yellow to a crimson colour. The precipitate is then to be separated by passing it through a linen cloth, and dried; after which, reduce it to powder, and digest in three gallons of alcohol, at thirty-six degrees, in a water bath, for several hours, at a moderate heat. Separate this solution from the calcareous precipitate, and distil off three-fourths of the alcohol. There then remains a strong solution of rhubarbine, to which add as much sulphuric acid as will exactly neutralize it. Evaporate this slowly to dryness, without having access to atmospheric air. The residuum will be of a brownish-red colour, intermingled with brilliant specks, possessing a slightly pungent styptic taste, soluble in water, and its odour that of the native rhubarb." This residuum is the sulphate of rhubarb. (Sulphate of _rhubarbin._?) Mr. CARPENTER assures us, that this preparation contains the medicinal principle of the rhubarb, apart from its inert portion; and considers it as bearing the same relation to rhubarb, as the sulphate of quinia to the Peruvian bark. The Chinese rhubarb, at half the price, furnished twice as much rhubarbin as the reputed Russian, which Mr. C. considers to be spurious in the Philadelphia market, being the English prepared in imitation of the Russian.--_Philadelphia Journal of the Medical & Physical Sciences. May_, 1826. 68. _Alkaline Lozenges of Bicarbonate of Soda._--Mr. D'ARCET proposes the following formula for these lozenges:--Take of Bicarbonate of Soda, pure and dry, and in fine powder, 5 parts. Very white Sugar, in fine powder, 95 Mucilage of Gum Tragacanth, q.s. Essential oil of Mint, pure and fresh, 2 or 3 drops for about every 3 ounces of mixture of bicarbonate and sugar. Shake the bicarbonate and sugar in a well dried bottle, with the view of mixing them intimately. Withdraw the mixture from the bottle, and add the mucilage and oil of mint, blending the whole together on a marble. The mass obtained, is then to be divided into lozenges, which should weigh, when dried, about 15 grains each. As they slightly attract moisture, they ought to be kept in a dry place, or in well stopped bottles.