SOLANACEE 641 
- fractional distillation yields the alkaloid. This is a colourless — 
oily liquid, having at 15°C. the specific gravity 1°0111, and 
remaining liquid at —10° C. .It has an unpleasant, and when 
heated a pungent, acrid, tobacco-like odour; a burning taste, 
and a strongly alkaline reaction. Hxposed to air and light, it 
_ rapidly acquires a brown colour and is partly converted into a 
resinous compound. It boils near 250° C., but distils at a 
lower temperature, always leaving a residue. Its composition 
is C!°H!4N?, It absorbs water from the air, dissolves readily 
in water, and is separated from this solution by caustic potassa; 
Alcohol and ether dissolve it in all proportions, and it yields 
with acids neutral and acid salts, of which the former crystallize 
with. difficulty, and are mostly soluble in weak alcohol, but 
insoluble in ether. The alkaloid acquires a wine-red colour 
With strong sulphuric acid, and on heating the mixture is 
charred. Chlorine gas colours it deep-red or red-brown, When 
heated with a little hydrochloric acid a violet colour is pro- 
duced, which on the further addition of nitric acid changes té 
Mowish-red. The double salts with mercuric and platinic 
ride are sparingly soluble in cold water. Dried tobacco 
“leaves contain from 2 to 8, and occasionally as high as. 11 per — 
- cent. of nicotine. The alkaloid is present in all parts of the 
: green plant, as well as in the dried leaves, and, according to 
Kissling (1882), also in tobacco-smoke. Instead of nicotine, 
‘H. Vohl and H. Enlenburg (1871), found chiefly. collidine, 
with pyridine, picoline, and other bases of the same series 
in tobacco smoke, besides ammonia and traces of ethylamine ; 
d, in passing the vapours through potassa solution, hydro- 
eyanic, _hydrosulphuric, acetic, formic, butyric, valerianic, 
rbolic, and probably other acids were retained. (Stillé and 
Maisch.) 
~ According to Herr Dieser (Archiv. Mar. 31, 1889, p. 266) the 
id tartrate of nicotine can be obtained as a well crystallized — 
definite salt. He prepares it by adding to pure nicotine 
ot filtered alcoholic solution of tartaric acid, when 
acid tartrate tan asa white syrup. After cooling, — 
mors of the tartaric acid solution is added, so long. as it. con: 
> oh 
