ALKALOIDS. 613 



changed to green by an excess of the reagent, and is destroyed by 

 free acids or alcohol, but not by alkalies. (Plate VI., 2.) 



3. A fragment of iodic acid added to a strong solution of a mor- 

 phine salt is decomposed, with liberation of iodine, which imparts a 

 violet color to chloroform upon shaking the latter with the mixture. 



4. A mixture of 2 parts of morphine and 1 part of cane-sugar 

 added to concentrated sulphuric acid gives a rose-red color. 



5. Morphine dissolves in cold, concentrated sulphuric acid, forming 

 a colorless solution, which, after standing for several hours, turns 

 pink or red on the addition of a trace of nitric acid. 



6. Aqueous or acid solutions of morphine salts are precipitated by 

 alkaline hydroxides ; the precipitated morphine is soluble in potas- 

 sium or sodium hydroxide, but not in ammonium hydroxide. 



7. Neutral solutions of morphine afford yellow precipitates with 

 the chloride of gold or platinum, with potassium chromate or dichro- 

 mate, and with picric acid, but not with mercuric chloride. 



Heroin, C 17 H 17 (C 2 H 3 O 2 ) 2 NO, is diacetyl-raorphine, obtained by heating 

 morphine with acetyl chloride. It is a white powder, having a bitter taste, 

 alkaline reaction, and practically insoluble in water, easily soluble in hot alco- 

 hol. It readily forms salts with acids, the one usually employed being the 

 hydrochloride, which is a white powder, of bitter taste, soluble in 2 parts of 

 water and in alcohol. It is precipitated by alkalies, carbonates, and alkaloid 

 reagents. 



Apomorphine, C 17 H 17 NO 2 . When morphine is heated for some 

 hours with an excess of hydrochloric acid, under pressure to 150 C. 

 (302 F.), it loses water and is converted into apomorphine, a crys- 

 talline alkaloid valuable as an emetic. 



Apomorphine hydrochloride, C 17 H 17 NO 2 .HC1 (U. S. P.), is a grayish- 

 white salt which turns greenish when exposed to light and air. 



Analytical reactions : 



1 . Nitric acid produces a deep purple color fading to orange. 



2. Sulphuric acid containing a trace of nitric acid produces a blood- 

 red color fading to orange. 



3. Sulphuric acid containing a trace of selenious acid produces a 

 dark blue color, fading to violet, then turning black. 



4. Sulphuric acid containing a trace of ferric chloride produces a 

 pale blue color. 



Codeine, Codeina, C 18 H 21 NO 3 .H 2 O =- 314.83. A white crystalline 

 powder, sparingly soluble in cold water, easily soluble in alcohol and 

 chloroform. It is neutral to litmus and has a faintly bitter taste. 



