RELATION OF NICOTINE TO QUALITY OF TOBACCO. 18 
and malic acids, and hence it follows that prolonged fermentation 
can never entirely remove the pungency of tobacco smoke due to the 
easily volatile nicotine. In the presence of an excess of citric acid, 
however, the greater portion of the acetic acid would be expelled 
because of its easy volatility. 
Citric acid is a normal and valuable constituent of tobacco, and its 
addition in moderate amounts could not therefore injure the quality 
of the tobacco in any way. There is every reason to believe that its 
addition during the fermentation process would prove highly bene- 
ficial to those types of cigar-filler tobacco which contain excessive 
quantities of nicotine not already in combination with citric or malic 
acids. This could probably be best applied by spraying the tobacco 
at the time of turning the bulks with an aqueous solution of such con- 
centration as to add from 1 to 2 per cent of the acid. 
COMPOSITION OF TOBACCO SMOKE. 
Now that we have seen that organic acids like citric, malic, or 
tartaric acid are efficient agents in preventing the nicotine contained 
in the tobacco from imparting an undesirable sharpness to the smoke, 
the question naturally arises as to the manner in which these acids 
effect this result. There would seem to be three possible ways in 
which this effect might be produced: (1) The nicotine salts of these 
acids are so difficultly volatile that the nicotine 1s decomposed in situ 
by the heat from the burning end of the cigar; (2) these salts, on 
account of their slight volatility at lower temperatures, are condensed 
from the smoke before it enters the mouth of the smoker and thus 
constantly accumulate in the unburned portion of the cigar; and 
(3) the nicotine passes into the smoke and enters the mouth of the 
smoker in the form of the salt instead of in the free state, thus losing 
its pungency or biting qualities. Which of these alternatives affords 
the true explanation can best be answered by smoking the tobacco 
in a suitable apparatus and determining the amount of the nicotine 
contained in the smoke and that remaining in the unsmoked ends of 
the cigars. 
A number of investigators have endeavored to study the composi- 
tion of tobacco smoke, but the problem presents many difficulties 
in the matter of securing satisfactory analyses. Without attempting 
to enter into this subject fully, it may be said in brief that the smoke 
is, in the first place, mixed with large amounts of nitrogen and small 
quantities of oxygen derived from. the air used in the combustion. 
In addition to these, the smoke proper contains, as difficultly condens- 
ible gases, small but appreciable quantities of carbon monoxid, hydro- 
eyanic acid, and probably also hydrogen sulphid. These latter are 
three well-known poisonous gases, although the quantities contained 
in tobacco smoke are probably too small to be of any special signifi- 
141—1 
