[Footnote 21: ‘Bulletin de l’Académie de Méd. Belgique,’ ix, 304; ‘Jahrb. f. prakt. Pharm,’ xxiv, 313; &c.] This method, according to Stas, answers well for all the ALKALOIDS which are soluble in ether; including——ACONITIA, ANILINE, ATROPIA, BRUCIA, CODEIA, COLCHICINA, CONIA, DELPHIA, EMETINA, HYOSCYAMINE, MORPHIA (?), NICOTIA, PETININE, PICOLINE, SOLANINE, STRYCHNIA, VERATRIA, &c. By means of it Stas found nicotia in the heart-blood of a poisoned dog. With such alkaloids as are, however, only very sparingly soluble in ether (as morphia for instance), the result must, necessarily, be doubtful. To detect these, as well as all the alkaloids which are insoluble in ether, it is, therefore, necessary, as directed by Otto, to add to the alkaline fluid left by the decantation of the ether, sufficient solution of soda to dissolve the morphia, &c. (if any has separated), and after the expulsion of the last traces of the ether by a gentle heat, to add a concentrated solution of hydrochlorate of ammonia, and to allow the mixture to repose for some time in the open air. When MORPHIA is present, it separates under the form of small crystals.[22] Or the alkaline liquor may be diluted with distilled water, and treated with charcoal, and this with alcohol, in the manner noticed under method 4 (_below_). [Footnote 22: Otto’s ‘How to Detect Poisons.’] 4. (Graham and Hoffmann——slightly modified.) 2 or 3 oz. of purified animal charcoal are digested in about 1/2 gal. of the (neutral or only slightly acid) aqueous fluid under examination, with frequent agitation, for 10 to 12 hours, or longer. The liquid is then filtered, and the charcoal left on the filter is washed twice with cold distilled water. The charcoal is then boiled for 1/2 an hour with about 1/2 a pint of rectified spirit of 80 or 90%; the ebullition being conducted in a flask having a very long tube, open at both ends, fitted air-tight through the cork, to prevent loss of the alcohol by evaporation. The spirit, which now contains the alkaloid (if any was present in the original liquor), is next filtered whilst hot, and the filtrate is submitted to distillation until the whole of the alcohol is removed. A small quantity (commonly a few drops) of solutions of potassa is then added to the residual aqueous liquor, followed by 1 to 2 fl. oz. of pure ether, after which the whole is well agitated for several minutes, and allowed to repose for a short time. Lastly, the supernatant ether is decanted, and allowed to evaporate spontaneously, when the residuum (if any) left in the capsule may be tested by reagents, as before. This method was devised for the detection of STRYCHNIA and NUX VOMICA in malt-liquors; but it is equally applicable to the detection of ANY ALKALOID which is soluble in ether. The CHARCOAL TEST may also be employed to detect alkaloids which are insoluble in ether; but then the base must be sought in the aqueous residuum obtained by the evaporation of the alcohol.[23]