370 Chemical Observations and Experiments on Tobacco. 
hue ; decrepitates before the fire, and seems to enjoy neutral proper- 
ties. 
12. Nicotia. 
There is not a more delusive term in modern chemistry, than Lig- 
nin: an analyst might be induced by this term, to abandon his re- 
searches on vegetables, after alechol, ether and water, at all tempe- 
ratures, had acted on them; for, after digestion in these substances, 
plants are’ supposed to be exhausted of their principles ; yet nothing 
ean be more gratuitously asserted. Quercia was obtained from oak 
bark thus depurated by ether, spirit and water, and Tobacco leaves 
similarly treated, and forming what chemists would call Lignin, af- 
forded a new alkali more strictly approximating to quercia in chemi- 
cal habitudes than to any other known salifiable base. 
Still Nicotia exists in a small quantity in the infusion and sdeutio’ 
of the leaves ; but it may be more readily developed by treating with 
sulphuric acid the Tobacco, well edulcorated with ether, alcohol and 
peers, -and evaporating nearly to dryness. 
erystals of the sulphate being carefully washed, may che de- 
<ulihosed by aqua ammonie, which, combining with the acid, precip- 
itates Nicotia. 
This substance does not appear to be susceptible of a erystalline 
form ; it is of a dull yellowish white color, tasteless, inodorous, plas- 
tic, abi pulverulent; insoluble in ether, alcohol and water ;. soluble 
in excess of acids, and decomposed by heat; all its salts are tasteless, 
and insoluble, unless acid predominate, and may be readily decom- 
posed by ammonia. Sulphate of nicotia crystallizes in asteroid 
needles, which, under the microsccpe, assume the form of quadran- 
gular prisms. It is soluble in water, and contains a slight excess of 
acid, a circumstance which may serve to distinguish it from quercia. 
- Hydro-chlorate (muriate) of Nicotia is aggregated in stars, usually 
Soniaioch of from five to six crystals. 
-» Borate of Nicotia is white, insoluble, and unerystallizable. 
The most diagnostic property of Nicotia, is perhaps’ its entering 
into solution with the — — without — with them any 
Neaitioe compound. 
—_ Aug. 24th, 1829, No. 8 Lombard street. 
