12 MISCELLANEOUS PAPERS. 
The results of these tests are shown in the following table: 
TABLE II.—Nicotine soluble in petroleum ether in domestic filler tobacco before 
and after the addition of citric acid. 
Domestic 
Domestic |filler tobac- prioeas 
Nicotine content. lertoe Gol with sen 
CO, -4 |\Santa Clara 
bacco. nee At tobacco. ° 
Per cent. Per cent. Per cent. 
Rotalimicotime .. Voss. csc ee ee ee ee Ce Eee eee 2.20 Dealt 1.33 
Nicotine insoluble im petroleum ether == a= =e —ee = seer eee 0. 76 1.66 0.79 
‘OH Tee”? SINT CO DIME! = cites e a ahs tae a Ces a rs eV 1.44 | 0.47 0.54 
It will be observed that two-thirds of the total nicotine contained 
in the domestic filler tobacco is in the easily volatile form which exists 
either in the free state or loosely combined with weak acids and that 
the addition of citric acid renders the greater portion of this insoluble 
in petroleum ether. The fact that the nicotine is not made wholly in- 
soluble by the addition of the acid is accounted for partly by reason of 
the shght solubility of the nicotine citrate in petroleum ether, but 
mainly because the solution of citric acid added had not diffused 
throughout the leaf tissue. Better results could be obtained by add- 
ing the citric acid solution before the fermentation process is com- 
pleted, thereby affording a better opportunity for the even diffusion 
of the acid through the leaf. Even under these unfavorable condi- 
tions the soluble portion of the nicotine was reduced below that of the 
mild Santa Clara sample. 
Samples of this tobacco to which the citric acid had been added 
were made into cigars which were tested by a number of persons, and 
the universal opinion has been that the sharpness or pungency of the 
smoke has been almost entirely removed by this treatment. Other 
similar acids, such as malic and tartaric acids, are also efficient in 
overcoming this property of the smoke, but oxalic acid does not give 
satisfactory results. The easily volatile fatty acids, such as acetic 
acid, form easily volatile salts with nicotine and hence do not produce 
any decided influence in this respect. It has already been stated, 
moreover, that these salts are soluble in petroleum ether. 
Citric and malic, succinic, and finally acetic and butyric acids 
merely represent intermediate stages in the degradation by fermenta- 
tive processes of the sugars to carbon dioxid and water. Citric and 
malic acids exist in the leaf prior to the fermentation, and whether 
the quantity of these is diminished in this process depends in any 
given case on whether the loss occasioned by partial transformation 
of these into succinic, butyric, and acetic acids is made good by the 
formation of further quantities by fermentation of the sugars. Acetic 
acid is formed during the fermentation at the expense of the citric 
141—1 
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