268 roiscms : their effects and detection. [§§324,325. 
II.—Liquid Volatile Alkaloids. 
THE ALKALOIDS OF HEMLOCK—NICOTINE—PITURIE—SPARTEINE. 
1 . THE ALKALOIDS OF HEMLOCK (CONIUM). 
§ 324. The Conium maculatum, or spotted hemlock, is a rather 
common umbelliferous plant, growing in waste places, and flowering 
from about the beginning of June to August. The stem is from three 
to five feet high, smooth, branched, and spotted with purple ; the 
leaflets of the partial involucres are unilateral, ovate, lanceolate, with 
an attenuate point shorter than the umbels ; the seeds are destitute of 
vittse, and have five prominent crenate wavy ridges. The whole plant 
is foetid and poisonous. Conium owes its active properties to the 
liquid-alkaloids Coniine and y-Coniceine, with a crystalline alkaloid, 
Conhydrine. Small quantities of Pseudoconhydrine and Methylconiine 
also occur in the plant. The alkaloids are in the plant combined with 
malic and caffeic acid. 
§ 325. Coniine (conia, conicine), (C 8 H 16 N)—specific gravity 0-862 
at 0°, 0-845 at 20° ; melting-point, —2-5° ; boiling-point, 166-6°. Pure 
coniine has been prepared synthetically by Ladenburg, and found to 
be a-propyl-piperidine, C 5 H 9 NC 3 H 7 , but the synthetically prepared 
piperidine has no action on polarised light. By uniting it with dextro- 
tartaric acid, and evaporating, it is possible to separate the substance 
into dextro-a-propyl-piperidine and lsevo-a-propyl-piperidine. The 
former is in every respect identical with coniine from hemlock ; it is a 
clear, oily fluid, possessing a peculiarly unpleasant, mousy odour. One 
part is soluble in 150 parts of water, 1 in 6 parts of ether, and in almost 
all proportions of amyl alcohol, chloroform, and benzene. It readily 
volatilises, and, provided air is excluded, may be distilled unchanged. 
It ignites easily, and burns with a smoky flame. It acts as a strong 
base, precipitating the oxides of metals and alkaline earths from their 
solutions, and it coagulates albumen. Coniine forms salts with hydro¬ 
chloric acid (C 8 H 15 N.HC1), phosphoric acid, iodic acid, oxalic acid, and 
tartrate, which are in well-marked crystals. The sulphate, nitrate, and 
acetate are, on the other hand, non-crystalline. 
If coniine is oxidised with nitric acid, or bichromate of potash, and 
diluted sulphuric acid, butyric acid is formed ; and since the latter has 
an unmistakable odour, and other characteristic properties, it has 
been proposed as a test for coniine. This may be conveniently performed 
thus : — A crystal of potassic bichromate is put at the bottom of a test 
tube, and some diluted sulphuric acid with a drop of the supposed 
coniine added. On heating, the butyric acid reveals itself by its odour, 
1 The saturated watery solution of coniine at 15° becomes cloudy if gently warmed, 
and clears again on cooling. 
