HEMLOCK. 
§ 325-1 
and can be distilled into baryta water, the butyrate of baryta being 
subsequently separated in the usual way, and decomposed by sulphuric 
acid, etc. 
Another test for coniine is the following :—If dropped into a solution 
of alloxan, the latter is coloured after a few minutes an intense purple- 
red, and white needle-shaped crystals are separated, which dissolve in 
cold potash-lye into a beautiful purple-blue, and emit an odour of the 
base. 1 Dry hydrochloric acid gives a purple-red, then an indigo-blue 
colour, with coniine ; but if the acid is not dry, there is formed a bluish- 
green crystalline mass. This test, however, is of little value to the 
toxicologist, the pure substance alone responding with any definite result. 
The ordinary precipitating agents, according to Dragendorff, act as 
follows :— 
Potass, bismuth iodide. 
1 : 2000, a strong orange precipitate. 
1 : 3000, the drop of the reagent is surrounded with a muddy border. 
1 : 4000, the drop of the reagent is surrounded with a muddy border. 
1 : 5000, still perceptible. 
1 : 6000, the last limit of the reaction. 
Phosphomolybdic acid gives a strong yellow precipitate; limit, 
1 : 5000. 
Potass, mercuric iodide gives a cheesy precipitate ; limit, 1 : 1000 in 
neutral, 1 : 800 in acid, solutions. 
Potass, cadmic iodide gives an amorphous precipitate, 1 : 300. The 
precipitate is soluble in excess of the precipitant. (Nicotine, under 
similar circumstances, gives a crystalline precipitate.) 
Fliickiger recommends the following reaction : 2 —“ Add to 10 drops 
of ether in a shallow glass crystallising dish 2 drops of coniine, and cover 
with filter-paper. Set upon the paper a common-sized watch-glass 
containing bromine water, and invert a beaker over the whole arrange¬ 
ment. Needle-shaped crystals of coniine hydrobromine soon form in 
the dish as well as in the watch-glass.” Hydrochloric acid, used in the 
same way, instead of bromine water, forms with coniine microscopic 
needles of coniine hydrochloride; both the hydrobromide and the 
hydrochloride doubly refract light. Nicotine does not respond to 
this reaction. 
Coniine forms with carbon disulphide a thiosulphate and a sulphite. 
If carbon disulphide, therefore, be shaken with an aqueous solution of 
coniine, the watery solution gives a brown precipitate with copper sul¬ 
phate, colours ferric chloride solution dark brown-red, and gives a milky 
opalescence with dilute acids. If coniine itself is added to carbon 
1 Schwarzenbach, Vierteljahrsschr. f. prakt. Pharm., viii. 170. 
2 Reactions, by F. A. Fliickiger, Detroit, 1893. 
