18 



highly improbable. Other iuvesti gators, for instance, Jenkins, have 

 proved that the nitrate content nndergoes only an insignificant decrease,^ 

 and still others, as Fesca and Behrens, assert that the nitric acid disap- 

 pears completely, probabl}' by reduction. These contradicting state 

 ments may be due to the great variations occurring in the nitrate per- 

 centage. A small amount might disappear completely while a larger 

 amount decreases but little, although in both cases the absolute amount 

 disappearing may be the same. 



The writer examined, qualitatively, both fresh and fermented leaves 

 from the same farm near Quiucy, Fla., and found a moderate amount of 

 nitrate in both. The samples of tobacco examined by Jenkins con- 

 tained from 1.89 to 2.59 i^er cent of nitric acid (N2O5) at a water content 

 of 23.5 to 27.5 per cent, while Behreus's samples contained only 0.2 per 

 cent of this acid in the dry matter. From the disappearance of such a 

 small amount of nitric acid, it cannot be inferred that larger quantities 

 would disappear entirely. In one of Jenkins's samples the amount of 

 nitric acid diminished from 2.59 to 2.35, that is, a diminution corre- 

 sponding to 0.4 per cent calculated for dry matter of the wrapper leaves. 

 Dambergis observed variations of nitric acid in Greek tobacco of com- 

 merce of from 0.5 to 3.37 per cent of the dry matter. Kot only the mode 

 of manuring, but also the nature of the soil and the weather, intluence 

 the nitrate content of the plants, hence large differences can not be a 

 matter of surprise. 



The principal changes which take place during the sweating or fer- 

 mentation i^rocess, as found by various investigators, may be summed 

 up as follows: 



(1) Decrease of nicotine. 



(2) Increase of ammonia. 



(3) Increase of alkaline reaction. 



(4) Disappearance of sugar. 



(5) Decrease of nitrate. 



(6) Improvement of flavor and aroma. 



The cold sweat which unfermented tobacco undergoes, and which 

 corresponds with the aging of wines, may be intentionally carried on 

 for as long as two years, where the main fermentation process has to be 

 shortened for any reason or is not thoroughly completed. Fully and 

 perfectly fermented leaves do not require this cold sweat, and the 

 manufacturers of a good product prevent after-fermentation by giving 

 such a degree of dryness in packing that further changes are stopped, 

 as after-fermentation might* finally lead to great difterences in the 

 product, which should be uniform. The interior of the piles or cases 

 would naturally become warmer, and the leaves would change more 



iConn. Expt. Sta., Ann. Kept. 1892. To Jenkins belongs the credit of having first 

 compared the fermented ■with the unfermented leaf in regard to the chemicarchanges. 



