RELATION OF NICOTINE TO QUALITY OF TOBACCO. 11 
In addition to these marked losses of nicotine by simple volatiliza- 
tion, there is a further decrease brought about by a process of oxida- 
tion. This latter transformation is a very slow one, and while it 
plays a part in the production of the brown color of tobacco it is 
not of importance as regards the total nicotine content. The slow 
oxidation of the nicotine to thick, brown-colored, tarry substances 
begins in the curing shed and is a continuous process thereafter, af- 
fecting alike the difficultly volatile and the easily volatile forms. 
EFFECTS OF ORGANIC ACIDS ON THE NICOTINE CONTENT OF 
TOBACCO. 
It has already been pointed out that, while the true physiological 
effect produced by the smoke of a given sample of tobacco depends 
essentially on the total nicotine content, one important factor pertain- 
ing to the strength of the tobacco as this term is generally under- 
stood—i. e., the sharpness of the smoke—i 
is the amount of the 
nicotine present which acts as if it were in the free state in that it is 
readily volatile. Furthermore, it has been shown that this easily 
volatile form of the nicotine is readily soluble in petroleum ether, 
while the nicotine which is in combination with malic and citric acids 
is not soluble. It follows, therefore, that the sharpness shown by the 
smoke of any tobacco should be removed either by extracting the 
tobacco with petroleum ether or, equally as well, by adding a sufhi- 
cient quantity of malic or citric acid to combine with all the nicotine 
present. 
We have made a number of experiments along this line with a 
sample of domestic filler tobacco which was especially well adapted 
for this purpose, and the results appear to justify fully the above: 
conclusions. This tobacco was of excellent quality in nearly every 
respect except that the smoke was extremely sharp and pungent, so 
that it was necessary to blend the tobacco with some other very mild 
type before using it for the manufacture of cigars. This filler was 
classed as a strong, very heavy type, although the total nicotine 
content was only 2.20 per cent, while many of our domestic filler 
types contain as much as 5 per cent of nicotine, The amount of this 
nicotine soluble in petroleum ether was determined. To a portion 
of the tobacco about 2 per cent of citric acid was added in aqueous 
solution by spraying, after which the sample was cased down for 
two days to allow the citric acid to diffuse through the leaf as far 
as possible. The nicotine in this sample before and after extraction 
with petroleum ether was then determined. For comparison, a sam- 
ple of imported Cuban filler known as “ Santa Clara,” which is a 
very mild type and which showed only a slight sharpness in the 
smoke, was also tested as to the amount of nicotine soluble in petro- 
_leum ether. 
141—1 
