274 TOBACCO PRODUCTION IN THE UNITED STATES. 



2. CITRIC AND MALIC ACIDS. These substances, especially iu combination with bases are readily susceptible 

 of fermentation. In tbe case of citric acid, Buchner (Ann. Cheat. Phunii., xxlviii, 208) 1'ouud that under the 

 action of ferments, alkaline citrates are gradually transformed, yielding first acetates, and subsequently carbonates 

 of the alkaline base. Personne (Comptes-Rendm, xxxvi, 197) observed that crude calcium citrate (the juice 01 

 lemons neutralized with chalk) passes rapidly into fermentation, yielding acetic and butyric acids, and that the 

 change is still more rapid when beer yeast is added. 



Dessaigues (Ann. Chem. Pharm,, Ixx, 102) observed the formation of succiuic acid by the spontaneous 

 fermentation of neutral calcium malate. Liebig (ibid., Ixx, 303) obtained the same results through fermentations 

 produced by the addition ef yeast or cheese iu small proportions. If the temperature or the quantity of cheese 

 exceed a certain degree or proportion, no succinic acid is formed, or that produced is immediately decomposed and 

 there is produced butyric acid, some acetic acid and a colorless, volatile, oily substance possessing the odor of 

 apples, the nature of which was not further determined, but which would seem to consist of the compound ethers 

 of the acids formed in the fermentation. 



3. ALBUMINOIDS. These substances as a class, and in the moist state, are very susceptible to fermentative or 

 putrefactive change. The only product of this decomposition that has been observed to form during the 

 fermentation of tobacco is ammonia, which is evolved freely during the fermentation of tobacco for snuff. While 

 undergoing such changes the albuminoids become active ferments. Pelouze (Comptes-Rendm, xliv, US) has shown 

 that in the absence of free mineral bases the decomposition of organic nitrogenous substances by fermentation or 

 putrescence is unattended by the formation of nitric acid, but that, on the contrary, the nitrates, if already 

 present, are decomposed with evolution of ammonia. 



4. NITRIC ACID. In spite of the fact just mentioned, and the, additional fact communicated by Pelouze and 

 Fr^my (op. cit., iv, 655) that the juice of tobacco, in a putrescent state, decomposes nitric acid, liberating nitrous 

 oxide, it appears that nitric acid is not changed during the fermentation of tobacco. The following analyses made 

 at the laboratory of the government tobacco manufactory at Paris show that even the prolonged fermentation to 

 which snuff is subjected during the operations of manufacture does not cause any perceptible change in the 

 proportion of nitric acid contained therein : 



PEOPORTION OF NITRIC ACID IN TOBACCO DURING THE DIFFERENT STAGES OF FERMENTATION FOR SNUFF. 



Percent, of 



Tobacco: nitric acid. 



Fermented in heaps 



First fermentation in cases -. 0. 73 



Second fermentation in cases 0. 70 



Third fermentation in cases 0. 72 



Fourth fermentation in cases - 0. 7sJ 



5. OTHER CONSTITUENTS. Concerning the ther constituents of tobacco there is no evidence to show that they 

 are liable to alteration during the processes of fermentation to which tobacco is subjected during the operation of 

 curing. 



Apart, therefore, from the destruction of sugar, it is manifest from the foregoing that the changes in composition 

 attending the fermentation of tobacco must be restricted chiefly to the albuminoids and organic acids. The change 

 in the albuminoids can only be observed in the general effect of fermentation on the quality of the tobacco, especially 

 when used for smoking, and its extent is only measured to a certain degree by the evolution of ammonia and the 

 attendant reduction in the percentage of total nitrogen. For the most part the albuminoids are transformed into 

 substances of undetermined character, according to the statement of Pelouze and Fre~my, already cited, substances 

 similar to the humus bodies. That this change has an important effect on the quality is evident from the marked 

 difference between the odor of the smoke of fermented and of unfermented tobaccos. 



In the case of the organic acids (citric and malic acids) it will be seen from the foregoing that these acids are 

 susceptible of several distinct species of fermentative change, of which the three following have been observed and 

 studied : 



1. Neutral calcium malate (Dessaignes and Liebig) is decomposed, with formation of succinic acid. 



2. In presence of a large quantity of ferment, or in cases where the temperature is somewhat elevated, the 

 fermentation yields only acetic and butyric acids, and a volatile substance of fruity odor (Liebig). 



3. Alkaline citrates are transformed first into acetates, and finally into carbonates of the alkaline bases (Buchner;, 

 or they are transformed into acetates and butyrates (Persoune). 



In view of the fact that tobacco is very rich in albuminoids, which, when in a decomposing state form the most 

 active ferments, the first species of fermentation of malic acid can hardly be supposed to occur. We have, therefore, 

 to deal solely with the second and third cases. 



The extent to which differences in composition may result from differences iu kind and degree of fermentation 

 in one and the same variety of tobacco is instructively shown by the two analyses of "Perique" tobacco; the one 

 (28) "cured in its juices", the other (37) "air-cured". The sample "cured in its juices" contains but little over 

 one- fourth of the citric acid, but one-half of the malic acid, and about six times the amount of swetic acid contained 



889 



