6S 
OBSERVATIONS ON NICOTINE, ETC. 
ART. XXIIL— OBSERVATIONS ON NICOTINE, WITH A DESCRIP- 
TION OF A METHOD FOR DETERMINING ITS AMOUNT IN 
LEAF AND MANUFACTURED TOBACCO. 
By M. Schloessing. 
The following is the most advantageous method for pre- 
paring nicotine. Tobacco is treated with water, and the 
solution concentrated ; the extract is dissolved in alcohol, 
which after decantation is likewise concentrated ; this last 
extract is now treated with potash, then agitated with aether, 
which dissolves the nicotine and also some foreign substances, 
which are got rid of by precipitating the alkaloid in the 
state of oxalate. This precipitate is washed by agitating it 
with aether, then treated with potash, again dissolved in 
aether, and submitted to distillation. The residue of the 
distillation is coloured but limpid, and contains, besides 
nicotine, water, 8ether and ammonia; a temperature of 284° 
maintained for 12 hours, and assisted by a current of dry 
hydrogen, suffices to expel these three bodies, so that the 
nicotine passes pure and colourless, when the temperature 
is subsequently raised to 356°. 2 lbs. of good tobacco, 
grown in the department of Lot, is capable of yielding by 
this process from 50 to 60 grms. of nicotine. 
The formula for nicotine, C 20 H 14 N 2 , proposed by M. 
Melsens, is confirmed by my analyses; its equivalent, 
1012.5, appears however to require doubling, for an equiva- 
lent of sulphuric acid neutralizes twice 1012.5; and nicotine 
is a powerful base, which precipitates the oxides of man- 
ganese, iron, and silver; it is therefore not very probable 
that its sulphate, which is neutral towards litmus paper, is 
in reality a subsulphate. The above view is also confirm- 
ed by the following fact: — If some nicotine is placed in a 
