RELATION OF NICOTINE TO QUALITY OF TOBACCO. g 
tobacco in at least two forms, one of which is soluble in petroleum 
ether while the other is practically insoluble. 
Tobacco normally contains relatively large quantities of malic 
and citric acids, from 5 to 10 per cent, a portion of which is in 
combination with potash or lime and is of great importance in con- 
nection with the burning qualities of the leaf. Of these acids the 
portion above that required for combining with the lime and potash 
is doubtless largely combined with nicotine. 
Nicotine, though quite volatile in the free state, is strongly basic 
and forms comparatively stable salts with acids which are not readily 
volatile. The nicotine salts of the difficultly volatile polybasic or- 
ganic acids, such as malic, succinic, citric, and oxalic acids, are prac- 
tically insoluble in petroleum ether; and, hence, the nicotine in com- 
bination with these acids would not be removed by extraction with 
this solvent. There seems to be no reason for supposing that freshly 
cured tobacco contains any of the volatile fatty acids, such as acetic 
and butyric acids, but it is well known that these acids are formed 
in the fermentation process from the malic and citric acids, or pos- 
sibly more directly from succinic acid, which is itself formed by 
the fermentation of the citric and malic acids. Acetic acid, like 
nicotine, is easily volatile, and so nicotine acetate is also readily 
volatile. Moreover, this salt is readily soluble in petroleum ether. 
Ammonia is likewise a product of the fermentation of tobacco, and 
the small quantity of acetic acid formed in the fermentation of 
tobacco and which escapes volatilization is to be found in combina- 
tion with either ammonia or nicotine. 
Practically all tobaccos appear to contain more nicotine than is 
required for neutralizing all of the stronger organic acids which are 
not already in combination with mineral or inorganic bases. In other 
words, it appears that a portion of the nicotine contained in tobacco 
is present in practically a free state. It possibly does not exist in an 
absolutely free condition, but rather in loose combination with very 
weak acids of the order of tannic acid or those derived more directly 
from the splitting of the chlorophyll constituents. Such unstable 
salts would act in most respects like the free base. At any rate, the 
greater portion of the nicotine removed from tobacco by extraction 
with petroleum ether can be titrated with sulphuric acid directly, the 
same as if it were in the free state. 
EFFECTS OF FERMENTATION AND AGING ON THE DiFFERENT 
FORMS OF NICOTINE IN TOBACCO. 
It has long been known that there is a decided loss of nicotine in 
the fermentation process, and the amount varies from 10 to 15 per 
cent in the case of wrapper-leaf tobaccos to as much as a third of the 
total nicotine content in filler types. Different opinions have been 
7034—Bul. 141—09——2 
