CHEMICAL ANALYSES OF TOBACCO. 265 



The leaves marked No. 4 were the upper leaves from the same stalk that furnished the leaves marked No 3. 



The foregoing results would show that the relative proportion of the nicotine increases with the age and 

 development of the leaves. According to the same author, although the green leaves contain more nicotine than 

 the fermented leaves, the nicotine odor is not perceptible in the former; it appears only after fermentation. 



NICOTIANINE. A volatile substance, of the consistence and appearance of camphor, possessing the odor of 

 tobacco, and an acrid, aromatic, and bitter taste. According to the analysis of Barral (PELOUZE ET FREMY : Traitc 

 de Chimie, T. iv, p. 033), it possesses a composition in accordance with the formula CzaHjjNjOa. It is chemically 

 an indifferent substance, forming no compounds with acids or alkalies, and is supposed to be the substance to which 

 the characteristic odor and flavor of tobacco are chiefly due. 



BESINOUS AND FATTY SUBSTANCES. Tobacco contains a considerable proportion of resinous and fatty 

 substances, concerning the nature of which as yet little is known. That the odor of the smoke is greatly influenced 

 by these substances is more than probable, and this would appear to be especially true as regards the question of 

 their resinous or fatty nature. The finely flavored tobaccos of Havana and Porto Eico are, according to Nessler 

 (op. cit., p. 29), richer in such substances than many European tobaccos, the smoke of which is strongly charged with 

 the odor of burning fat, whence he infers that in the first named varieties the resinous substances are present in 

 excess of the fats. 



STAECH (CseHajOai). All tobaccos contain starch, usually in small proportions, although under certain conditions, 

 as in the experiments of Schloesiug (Comptes-Rendus, Ixix, 253), the amount may rise to over 19 per cent, of the 

 weight of tJie dry leaves. 



SUGAR (glucose, C 6 IIi 2 O 6 ) is also present in the fresh (green) plant, usually in small proportions. When the 

 tobacco is fermented in the operation of curing, the sugar usually disappears. 



NITROGENOUS SUBSTANCES GENERALLY (ALBUMINOIDS). Beside nicotine and nicotianine tobacco contains 

 a large proportion of nitrogenous organic substances. Vauquelin (Annales de Chimie, Ixxi, 139) found vegetable 

 albumen in green tobacco, and his observations were confirmed by the investigations of Goupil (Comptes-Rendus, 

 July, 184G, No. 1), made under the direction of Fr6niy, and by the analysis of Posselt and Beitnann (Pharm. 

 Centralbl., 1847, 171). Tobacco that has become yellow or brown on drying, no longer contains the albuminous 

 substance above noted. The nitrogenous substances extracted from harvested and dried tobacco are brown, and 

 are to be regarded as the products of the more or less advanced alteration of the albuminous substances originally 

 present in the green leaf. These brown nitrogenous substances approach closely in their properties to the (so-called) 

 ulmic acid (PELOUZE ET FREMY, op. cit., iv, C3G). 



PECTIC ACID (Ci 6 n 22 Oi5, Fr6my) occurs in varying proportions in tobacco, and gives strength and stiffness to 

 the leaf. It has been generally assumed to exist in the tobacco in the state of calcium pectate. 



CITRIC ACID (C 6 H 8 O 7 ), MALIC ACID (C 4 H 6 O 5 ) AND OXALIC ACID (C 2 H 2 O 4 ). These acids are always present in 

 tobacco, the first two in large, the last in small proportions. They exert a very important effect on the quality of 

 the leaf. 



ACETIC ACID (C 2 H 4 O 2 ) is present in varying, and usually small, proportions, and is either wholly or at least 

 for the most part a product of fermentation. 



NITRIC ACID (I1NO 3 ) is present in certain cases in considerable quantity. According to Nessler (op. cit., pp. 

 22 and 28) the presence of this substance in tobacco is to be ascribed, either wholly or in part, to the decomposition 

 of other nitrogenous substances by fermentation with free access of air (nitrification). Eeasons will be hereafter 

 given which would appear to justify the opinion that this conclusion of Nessler's is erroneous, and that the nitric 

 acid in tobacco has entered the plant through the processes of nutrition (absorption by the roots) during the period 

 of its growth. 



AMMONIA (H 3 N) is present in all tobaccos, usually in small proportions. It is evidently a product of 

 fermentative change. Nessler (op. cit., p. 19) asserts that it does not occur in fresh (green) tobacco, and it is found 

 to be evolved in large quantities during the fermentation of snuff. (PELOUZE ET FREMY, T. iv, pp. 654 et seq.) 



CELLULOSE (CRUDE FIBER). This material constitutes the frame-work or skeleton of the cellular tissue as 

 distinct from the cell-contents. According to the proportion in which it is present, it bears a most important 

 relation to the character of the leaf, as regards the texture, and, in the case of smoking tobaccos, the combustibility 

 and general quality. According to Fr6my (PELOUZE ET FREMY, T. iv, p. 647) the proportion is usually from 6 to 11 

 per cent. It is greatest in fine tobaccos of close texture and least in coarse tobaccos of thick tissue. According to 

 Nessler (op. cit., p. 29), the quality of tobacco (for smoking) improves to a certain extent as the proportion of woody 

 fiber increases and that of the soluble organic (extractive) substances diminishes. 



ORGANIC SUBSTANCES OF UNDETERMINED CHARACTER. In addition to the substances previously 

 enumerated, tobacco contains certain other substances, the nature of which has not been investigated. Among 

 these are substances of a gummy consistence and indefinite chemical character, substances similar in properties to 

 the humus substances, possibly also the decomposition products of tannin, which latter substance, while often present 

 in the green leaf, is present only in faint traces in some of the less perfectly cured samples. 



MINERAL INGREDIENTS (ASH). The leaves of the tobacco plant are exceedingly rich in mineral ingredients, 

 ami the amount and nature of these is of essential influence on the quality of the material. 



859 



