mining in the alcoholic solution, and after the alcohol has been driven off, the quantity of sulphuric acid by means of a salt of baryta, and by subtracting this weight from that of the sulphate of the alkaloïd, the rest represents the quantity of the pure alkaloïd. The isolation of the alkaloïd is effected by distilling the sulphate with soda-ley, shaking the distillate with ether, decanting the ethereous liquid and evaporating by means of the air-pump. The investigation of the physical and chemical properties of the composition and constitution of the volatile alkaloïd is the object of further experiments. Table of Comparison between Baume's Scale and the Specific Gravity of Alcohol. Table Showing the Specific Gravity of Alcohol of Different Percentage by Weight at 60° F. Table showing the Specific Gravity of Alcohol of Different Percentage by Volume at 60° F. Table of Comparison between Cubic Centimeters and English Cubic Inches. 0.061024 cub. in. | 6 Cub. Centimeter = 0.366144 cub.in. 12345 1 Cub. Centimeter 0.122048 7 = 0.427168 = 0.488192 1 Litre = OMISSIONS AND ERRATA. Aconitin. Dr. C. R. A. Wright has shown that the use of alcohol acidulated with a mineral acid, for exhausting the root of Aconite, causes an alteration of the alkaloïds originally present; hence it is recommended, according to Duquesnel's method, to percolate by alcohol acidulated with tartaric acid, to evaporate at a low temperature, or, better still, in vacuo, to crystallise from ether after the separation of the base by sodium-carbonate, and to 'purify by conversion into a crystalline salt, for which purpose the hydrobromide is well fitted. Dr. Wright's formula for pure Aconitin=C33 H43 NO12.—(Blackett). Alstonin.-Alkaloïd of the bark of Alstonia constricta, F. v. M. Obtained by treating the alcoholic extract with water and a little hydrochloric acid, adding to the filtered solution a small excess of ammonia, dissolving the separated flocks in ether, evaporating the ethereous solution, and purifying the remaining A. by dissolving again in dilute acid and repeating the above process.--Orange yellow, brittle, pellucid mass, of very bitter taste, melts below 100°, and is carbonised in higher temperatures; dissolves easily in alcohol, ether, and dilute acids, sparingly in water. All its solutions in the dilute state exhibit a strong blue fluorescence, which is not affected by acids or alkalies. Its alcoholic solution has a slightly alkaline reaction. Alstonin combines with acids, but does not completely neutralise them. Hydrochloric and other strong acids, also alkalies, decompose it partly on evaporation in the water-bath to a dark-coloured acid substance. The hydrochloride of A. gives precipitates with the chlorides of platinum and mercury, the iodides of potassio-mercury and of potassiobismuth, bi-iodide of potassium, the phospho-molybdate and the phospho-tungstate of soda, bichromate of potash, picric acid, and by the alkalies and alkaline carbonates. Tannic acid does not precipitate the hydrochloride, but does so the acetate and the pure base. Concentrated nitric acid dissolves A. with crimson colour, yellow on warming; sulphuric acid reddish brown, afterwards dirty green; hydrochloric only effects a yellowish solution. Alstonin differs from Ditamin chiefly by its behaviour towards |