266 
POISONS : THEIR EFFECTS AND DETECTION. [§ 323 . 
attached to nitrogen may be determined, methyl being the only 
alcoholic radicle which occurs attached to the nitrogen of alkaloids. 
Herzig and Meyer have shown that when the hydriodic acid salt of 
the base is subjected to dry distillation, the methyl groups are eliminated 
as methyl iodide, and may be determined by means of silver nitrate. 
Thus it has been found that chrysanthemine and caffeine contain one 
methyl group ; cusohygrine and narceine contain two ; trigonelline, 
areeoline, methyl coniine, nicotine, hygrine, pseudopelletierine, atropine, 
cocaine, morphine, codeine, narcotine, and eserine contain one ; and 
lupinine, lupanine, cinchonine, and harmaline none. 
§ 323. Quantitative Estimation of the Alkaloids. —For medico¬ 
legal purposes the alkaloid obtained is usually weighed directly, but for 
technical purposes other processes are used. One of the most convenient 
of these is titration with d.n. acid, using a suitable indicator. 
Kippenberger 1 has shown, in a special research, that the choice of an 
indicator is not indifferent, some indicators giving to titration values for the 
alkaloids entirely erroneous ; he gives the following list of suitable indica¬ 
tors ; those in brackets may be used, but are not as suitable as the others. 
Atropine. —Iodeosin, (methyl-orange), azolithmin, hsematoxyhn, lacmoid, cochi¬ 
neal, uranine. 
Morphine. —(Iodeosin), cochineal, lacmoid. 
Aconitine. —Iodeosin, azolithmin, hsematoxyhn, cochineal. 
Veratrine. —Iodeosin, hsematoxyhn, cochineal, lacmoid. 
Thebaine. —Iodeosin, uranine, (hsematoxyhn), cochineal, lacmoid. 
Codeine. —Iodeosin, (azolithmin), uranine, hsematoxyhn, cochineal, lacmoid. 
Cocaine. —Lacmoid, uranine, cochineal, hsematoxyhn. 
Strychnine. —Iodeosin, azolithmin, (uranine), hsematoxyhn, cochineal, lacmoid. 
Brucine. —Iodeosin, azolithmin, (uranine), hsematoxylin, cochineal, (lacmoid). 
Nicotine. —(Iodeosin, uranine, cochineal), lacmoid. 
Coniine. —Iodeosin, (methyl-orange, azolithmin), hsematoxyhn, alkannin, cochi¬ 
neal, lacmoid, Congo-red. 
Sparteine. —Azolithmin, (uranine), hsematoxyhn, phenolphthalein, alkannin. 
Papaverine. —Lacmoid. 
A reagent of general application is found in the so-called Mayer’s 
reagent, which consists of 13-546 grms. of mercuric chloride and 49-8 
grms. of iodide of potassium in a litre of water. Each c.c. of such 
solution precipitates— 
Of Strychnine 
„ Brucine 
„ Quinine 
„ Cinchonine 
„ Quinidine 
„ Atropine 
,, Aconitine 
„ Veratrine 
,, Morphine 
„ Narcotine 
„ Nicotine 
„ Coniine 
•0167 grm. 
•0233 „ 
•0108 „ 
•0102 „ 
•0128 „ 
•0145 „ 
•0268 „ 
•0269 „ 
•0200 „ 
•0206 „ 
•00405 „ 
•00416 „ 
1 Zeit. f. anal. Chemie, 1900, p. 301, 
