ON NICOTINE. 
143 
tobacco contains two per cent., that of Maryland 2.3, that of 
Virginia 6.9, that of Alsace 3.2, that of Pas-de-Calais 4.9, that 
of the Nord 6.6, and that of the Lot 8. It is classed among the 
natural volatile vegetable alkalis, which are only three in number, 
namely, conicine, theobromine, and nicotine. This last is entirely 
composed of hydrogen, carbon, and nitrogen. It may be repre- 
sented as a compound of one equivalent of ammonia (NH 3 ) and 
of one of a hydro-carbon containing four equivalents of hydrogen 
and ten of carbon (H 4 C 10 ). It is now obtained by a much more 
simple process than was formerly adopted, which consists in 
passing the vapor of tobacco into water acidulated with sulphuric 
acid. Sulphate of nicotine is thus speedily produced, and this 
has to be decomposed by a strong alkali. It is then only neces- 
sary to apply sufficient heat to volatilize the nicotine. This mode of 
preparation indicates that smokers in respiring the smoke of 
tobacco introduce into their bodies a certain quantity of the 
vapor of nicotine. 
Characters of pure Nicotine. — It is in the form of an oleaginous, 
transparent, colorless, tolerably fluid, anhydrous liquid, of the 
density of 1.048, becoming slightly yellow with keeping, and 
tending to become brown and thick from contact with the air 
from which it absorbs oxygen ; its acrid odor resembles but 
slightly that of tobacco ; its taste is very burning. It volatilizes 
at 77° F., and leaves a carbonaceous residue. The vapor which 
rises presents such a powerful smell of tobacco, and is so irritating, 
that it is difficult to breathe in a room in which one drop of it has 
been spilt. If this vapor be approached with a lighted taper, it 
burns with a white smoky flame, and leaves a carbonaceous residue 
as an essential oil would do. It strongly blues reddened litmus 
paper. It is very soluble in water, in alcohol, and in fat oils, as 
also in ether, which easily separates it from an aqueous solution. 
The great solubility of nicotine in both water and ether forms an 
important fact in its chemical history, as the greater number of 
vegetable alkalis, not to say all, if they dissolve easily in one of 
these liquids, are not readily soluble in the other. 
Nicotine combines directly with acids, disengaging heat. Con- 
centrated pure sulphuric acid, without heat, produces with it a 
wine-red color ; on the application of heat to this it becomes thick, 
and acquires the color of the dregs of wine ; if it be boiled it 
