Sublime. Melt. /----------\ /----------\ Sublime, melt and Fahr. Cent. Fahr. Cent. MORPHINE } yield carbonaceous { 330° 165° 340° 171° STRYCHNINE} residue. { 345° 174° 430° 224° Melt. Sublime. /----------\ /----------\ Fahr. Cent. Fahr. Cent. ACONITINE } { 140° 60° 400° 204° ATROPINE } Melt, change { 150° 66° 280° 138° VERATRINE } colour, sublime, { 200° 93° 360° 182° BRUCINE } and { 240° 116° 400° 204° DIGITALIN } deposit carbon. { 310° 154° 310° 154° PICROTOXIN} { 320° 160° 320° 160° SOLANINE } { 420° 215° 420° 216° _Selmi’s method of extracting poisonous alkaloids in forensic investigations._ The alcoholic extract of the viscera, acidified and filtered, is evaporated at 65° C., the residue taken up with water, filtered to separate fatty matters, and decoloured by means of basic acetate of lead, leaving the solution in contact with the air for 24 hours. It is then filtered, the lead precipitated by means of sulphuretted hydrogen, and the solution after concentration repeatedly extracted with ether. The ethereal solution is then saturated with dry carbonic anhydride, which generally causes a precipitate of minute drops adhering to the sides of the vessel, and containing some of the alkaloids. The ethereal solution is then poured into a clean vessel, mixed with about half its volume of water, and a current of carbonic anhydride passed for about twenty minutes, which may cause the precipitation of other alkaloids not precipitated by dry carbonic anhydride. Usually the whole of the alkaloids present in the ether are thrown down by these means, but if not, the solution is dehydrated by agitation with Barium oxide, and then a solution of tartaric acid in ether added to the clear liquid, taking great care not to employ excess of acid. This throws down any alkaloid that may remain. In order to extract any alkaloids that may still remain in the viscera, they are mixed with Barium hydrate and a little water, and then agitated with purified amylic alcohol; the alkaloids may subsequently be extracted from the alcohol by agitation with very dilute sulphuric acid. A knowledge of the different solubilities of the alkaloids will be found an important auxiliary in their analysis. The following is a summary of the relative solubility of the most important of them. The figures denote the number of parts of the liquid required for their solution:—— _Absolute alcohol._——Strychnine insoluble; brucine soluble.