A Manual of the Detection of Poisons by Medico-chemical Analysis

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Baillière Brothers, 1862 - Chemistry, Forensic - 178 pages

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Page 63 - ... larger quantity of water; allows the insoluble portion to subside and decants; evaporates the clear solution rapidly; again decants from the freshly precipitated peroxide of manganese; and leaves the solution to crystallize by cooling. The crystals are then washed with a small quantity of cold water; dissolved in the smallest possible quantity of boiling water; and the solution left to crystallize by cooling. In this manner, needles are obtained f inch in length, and amounting in weight to about...
Page 157 - ... over during the solution is yellow, which colour does not proceed merely from the presence of chlorine, but from the constituents of the solution which are carried over mechanically. The acid is distilled until the liquid has a syrupy consistence, and congeals on cooling. The saline mass so formed is dissolved in the smallest possible quantity of water, and the solution is poured off with all due precaution.
Page 153 - Ticth of a grain dissolved in spirit and rubbed into the skin causes loss of feeling, lasting for some time. (" Lancet, March 29, 1856, p. 343.) There is a great difference in the properties of this alkaloid according to the mode in which it is prepared. (Bouchardat, " Ann. de Thérapeutique,
Page 164 - I have succeeded in isolating, without the least difficulty, these different alkaloids, previously mixed with foreign matters. I have thus been able to extract, by this process, morphine from opium, strychnine and brucine from nux vomica, veratrine from extract of veratrum, emetine from extract of ipecacuanha, colchicine from tincture of colchicum, aconitine from an aqueous extract of aconite, hyoscyamine from a very old extract of henbane, and atropine from an equally old tincture of belladonna.
Page 156 - It is founded on the observation, that the alkaloids form acid salts, which are soluble in water, and in alcohol, and that on decomposing a solution of this kind by means of an alkali, and agitating it with a sufficient quantity of ether, the liberated base dissolves in the ether. If the contents of a stomach, food, etc., are to be examined, they are mixed with double their weight of the strongest alcohol, from 10 to 30 grains of tartaric or oxalic acid are added, and the mass heated in a retort...
Page 163 - This produced a white precipitate, which was collected on a filter, washed with a little water and then dissolved in alcohol, which, on evaporation, left behind colorless crystals.
Page 94 - ... further addition of acetate of soda. The precipitate is collected on a filter, washed, dried, and ignited in a platinum dish after having been moistened with a few drops of nitric acid, and in this way a basic phosphate of iron is obtained perfectly free from protoxide.
Page 63 - If too little nitre is employed, part of the organic matter may remain unburnt, and arsenic may be volatilized from the carbonaceous mass ; on the other hand, too much nitre would interfere with the subsequent treatment of the mass. It is better to make a preliminary test with a small portion of the mixture, by introducing it into a small red-hot crucible, and observing whether the mass is perfectly white after deflagration. If it is black and carbonaceous, more nitre must be added.
Page 74 - ... strength be increased gradually, after their effect has been well exhausted, by the use of greater quantities applied by a quick flow, or the use of smaller quantities in a slow current distributed over a longer time of contact. Solution of Alum. — Half an ounce of roughly-powdered crystallized alum is dissolved in a small quantity of hot water, and the solution made up to one quart by means of cold and tepid water in such a manner as to ensure that the temperature of the solution should be...
Page 157 - Btill better in vacuo over sulphuric acid. The residue is exhausted with cold anhydrous alcohol; the extract is evaporated ; the residue is dissolved in the smallest possible quantity of water, and the solution saturated with bicarbonate of soda. The liquid is then agitated with from four to six times its volume of pure, rectified ether ; the alkaloid will be found in the ethereal solution. A small portion is tested for the volatile alkaloids (nicotine, conia,) by allowing it to evaporate spontaneously...

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