The substances are placed in a capacious flask, diluted if necessary with water to the consistence of a thin soup, and tartaric acid added to distinct acid reaction, and distilled. In this way phosphorus, prussic acid, carbolic acid, chloroform, chloral hydrate, nitrobenzol, aniline,[44] and alcohol may be separated and identified by the reactions given in the sections of this work describing those substances. [44] Aniline is a weak base, so that, although a solution be acid, some of the aniline distils over on heating. II. ORGANIC POISONS NOT VOLATILE IN ACID SOLUTION. Part No. II. is mixed with double its volume of absolute alcohol, tartaric acid added to distinct acid reaction and placed in a flask connected with an inverted Liebig’s condenser; it is then warmed for 15 to 20 minutes on the water-bath. After cooling, the mixture is filtered, the residue well washed with alcohol and evaporated to a thin syrup in a porcelain dish over the water-bath. The dish is then allowed to cool and digested with 100 c.c. of water; fat and resinous matters separate, the watery solution is filtered through Swedish paper previously moistened: if the fluid filtrate is clear it may be at once shaken up with ether, but if not clear, and especially if it is more or less slimy, it is evaporated again on the water-bath to the consistence of an extract: the extract treated with 60 to 80 c.c. of absolute alcohol (which precipitates mucus and dextrin-like substances), the alcohol evaporated off and the residue taken up with from 60 to 80 c.c. of distilled water; it is then shaken up with ether, as in Dragendorff’s process, and such substances as digitalin, picric acid, salicylic acid, antipyrin and others separated in this way and identified. After this treatment with ether, and the separation of the ether extract, the watery solution is strongly alkalised with caustic soda and shaken up again with ether, which dissolves almost every alkaloid save morphine and apomorphine; the ethereal extract is separated and any alkaloid left identified by suitable tests. The aqueous solution, now deprived of substances soluble in ether both from acid and from solutions made alkaline by soda, is now investigated for morphine and apomorphine; the apomorphine being separated by first acidifying a portion of the alkaline solution with hydrochloric acid, then alkalising with ammonia and shaking out with ether. The morphine is separated from the same solution by shaking out with warm chloroform.[45] [45] Hot amyl alcohol would be better (see “Morphine”). III. METALS.