274 poisons: their effects and detection. [§§ 334 , 335 - 
a frog, *44 to a pigeon, in a few minutes. In the seeds of Lupinus 
luteus there is a series of coniine-like substances, 1 but they do not give 
the characteristic crystals with hydrochloric acid. 
2. TOBACCO—NICOTINE. 
§ 334. The different forms of tobacco are furnished by three species 
of the tobacco plant, viz. Nicoticmum tabacum, y N. rustica, and N. persica. 
Havana, French, Dutch, and the American tobaccos are in the main 
derived from N. tabacum ; Turkish, Syrian, and the Latakia tobaccos 
are the produce of N. rustica. There seems at present to be little of 
N. persica in commerce. The following alkaloids have been isolated 
from the aqueous extract of tobacco :—Nicotine, C 10 H 14 N 2 ; Nicotim- 
ine, C 10 H 14 N 2 ; Nicoteine, C 10 H 12 N 2 ; and Nicotelline, C 10 H 8 N 2 . 
The general composition of the whole plant may be gathered from 
the following table :— 
TABLE SHOWING THE COMPOSITION OF FRESH LEAVES OF TOBACCO 
(POSSELT AND 
Nicotine and other alkaloids 
REINMANN). 
Per cent 
0-060 
Concrete volatile oil . 
.... 
0-010 
Bitter extractive.... 
• • • • 
2-870 
Gnm with malate of lime . 
.... 
1-740 
Chlorophyll . . . . 
• • 
0-267 
Albumen and gluten . 
• • • • 
1-308 
Malic acid . 
.... 
0-510 
Lignine and a trace of starch 
• • . • 
4-969 
Salts (sulphite, nitrate, and malate of potash, chloride 
of potassium, phosphate and malate of lime, and 
malate of ammonia) ...... 
0-734 
Silica ...... 
• . • • 
0-088 
Water . . . . 
. 
88-280 
100-836 
§ 335. Quantitative Estimation of Nicotine in Tobacco. — Keller’s 
process (J.C.S., Abs., 1899, ii. 193) gives fair results, and is as follows : 
—6 grms. of tobacco dried over quicklime are powdered and treated 
with 60 grms. of ether, 60 of petroleum ether, after the addition of 10 
c.c. of 20 per cent. KOH solution ; after digesting 3 -4 hours, 100 grms. 
of the ethereal liquid are placed in a 200 c.c. flask, and a strong current 
of air passed over to expel ammonia ; 10 c.c. of water, 10 c.c. of alcohol, 
and a drop of 10 per cent, solution of iodeosin are added and the whole 
shaken ; this causes the nicotine and iodeosin to pass into the aqueous 
liquid. D.n. HC1 acid is now added until the liquid is colourless ; the 
slight excess of acid is titrated back with d.n. ammonia. One c.c. of 
the acid equals 16-2 mgrms. of nicotine. 
1 Sievert, Zeitschrift fur Naturivissenscfuiflen, 1869. 
