§ 65. ESTIMATION OF ALKALOIDS. 61 



the hyoscine of Höhn and others. Its gold salt melts at a higher 

 temperature than that of atropine or hyoscyamine.] (See further 

 in § 174.) 



Einiline. — 1 cc. of the potassio-mercuric iodide precipitates 

 0'0189 gram emetine. The precipitate has the composition 



Coniine. — 1 cc. indicates 0*01 25 gram, coniine i)rovided that the 

 solution contain ;^ to 1 per cent, of the alkaloid, as little free acid as 

 possible, and, in addition, .3 to 4 per cent, of chloride of potassium. 

 If these conditions are complied with the composition of the pre- 

 cipitate will be (CjsHieNI)^ + Hglo (§§ 174, 180). 



Nicotine. — 1 cc, indicates 0"00405 gram nicotine; the composi- 

 tion of the precipitate is C^QH^gNoI^ + Hgl2. 



Stri/chnine and Bmcine. — 1 cc. precipitates 0'0167 gram strych- 

 nine and 0'0197 gram"] anhydrous brucine (in the latter case 

 as little free acid as possible should be present). The pre- 

 cipitates have the composition C2iH.,<,N20.,HI + Hgl.,, and 

 CosHooN.O.HI + HgL (§§ 174, 180). 



Colchicine. — 1 cc. precipitates 0'0317 gram colchicine, the con- 

 centration being about 1 to 600, and the solution containing 7 to 10 

 per cent, of sulphuric acid. The precipitate appears to contain 

 four equivalents of colchicine to one of Hgl^. 



Morphine and Narcotine. — 1 cc. corresponds to 0'02 gram crys- 

 tallized morphine^ and 0'0213 gram narcotine. (See also § 174.) 



Veratrine, sahadilline, and sabatrine. — 1 cc. indicates, according 

 to Masing,^ 0'0296 gram veratrine. Little sulphuric acid only 

 should be present and a correction of 0-000068 gram veratrine 

 made for every cc. of liquid. According to the same chemist, 

 1 cc. of the potassio-mercuric iodide is equivalent to 0-0374 gram 

 sabadilline and 0-03327 gram sabatrine. Correction for every cc. 

 0-00005 gram of the former and 0-0000408 gram of the latter 

 (§ 174). _ _ 



Physostigmine. — 1 cc. precipitates 0-01375 gram jihysostigmine 

 (Masing). Correction for every cc. 0-000105 gram. The com- 

 position of the precipitate is assumed to be C;^-H2ijS'30oHI -i- Hgl.,. 

 (See also § 174.) 



^ This formula, also, will have to be altered as soon as analyses of the pure 

 emetine prepared by Podwissotzki are published. 



■^ For the application of potassio-cadmic iodide to the quantitative determina- 

 tion of opium alkaloids see Lepage, Kepert. f. Pharm. 1875, 613. 



^ Archiv d. Pharm, ix. 310 (Journ. Chem. Soc. xxxii. 369). 



