THK PREPARATION OF BURNT II AN 129 



increase being prevented by turning the heap, so that the outer layers of the 

 first heap become the central portion of the new one. This fermentation is d in- 

 to the action of bacteria, and was studied thoroughly by E. SUCHSLAND (I. and 

 1 1 .), who, however, furnished but scanty reports thereon. A patent was granted 

 to him in connection with the use of pure cultures of bacteria for the purpose of 

 favourably influencing the fermentation of tobacco. He prepared pure cultures 

 of bacteria from fine West Indian tobacco and transferred them to inferior 

 German tobacco in course of fermentation. By this means the flavour of the 

 latter was so greatly improved that it was no longer recognisable as such even 

 by connoisseurs and experienced smokers of native tobacco. 



The chemical changes hereby produced have been investigated by J. BEHRENS 

 (II.), according to whom the loss of matter amounts to 4 to 5 per cent., and 

 consists principally of soluble carbohydrates and fixed organic acids, the former 

 disappearing almost entirely. Carbonic acid is evolved as the result of these 

 changes, while FESCA and IMAI (I.) ascertained that nitrates are no longer 

 present in the fermented mass. The amount of nicotine is also reduced, 

 only 70 per cent, of that originally present being afterwards found (in one 

 experiment) by Behrens. 



The flora of the fermenting tobacco heap does not consist solely of bacteria. 

 For example, JOH. BEHRENS (III.) frequently met with the Aspergillus fumigatus 

 already mentioned, and Davalos and Behrens also very often detected Monilia 

 Candida, remarks on which will be given in a subsequent chapter. 



A few researches have been made into the fermentation of snuff, the most 

 important being those carried out by TH. SCHLOSING (I. and II.) relative to the 

 chemical changes involved. With respect to the part played by micro-organisms 

 he expressed himself as follows : " The fermentation begins at the ordinary 

 temperature under the predominant influence of micro-organisms, but above a 

 certain (still to be determined) limit, which is over 40 C. and below 70 C., and 

 is probably about 50 C., the changes become purely chemical reactions in which 

 the living organisms have no longer any share." When giving utterance to this 

 opinion Schlosing was unacquainted with the newer researches in connection 

 with the heat-loving organisms which thrive at 70 C. It is therefore desirable 

 that his experiments should be repeated and extended, with this fact borne in 

 mind. 



The tobacco subjected to this fermentation is usually moistened with a liquid 

 containing sugar, syrup, honey, and the like, in addition to various aromatics, 

 and not infrequently alcohol as well. In many cases this " sauce " also has 

 added to it wine yeasts, particularly for the grades known as St. Omer, St. 

 Vincent, and Paris tobaccos. These additions (found by experience to be partly 

 essential and partly useful) probably furnish the material for, on the one hand, 

 a weak alcoholic fermentation, and, on the other, for the formation of esters. 

 More detailed knowledge is, however, lacking with regard to this primary 

 fermentation, and to the subsequent after-fermentation of the tobacco, either 

 packed tightly into casks or rolled up in "pigtail " form and wrapped in linen 

 cloths. The snuff yielded by the latter method is finer than that obtained by 

 the quicker cask-fermentation process. More definite researches on this subject 

 are highly desirable. 



106. The Preparation of Burnt Hay 



must also be briefly described in this place. There are two chief methods, 

 differing from one another, for the preservation of green fodder, viz., either by 

 acidifying it, allowing it to ferment, and so producing " sour " fodder or ensilage 

 for which see also chapter xxvi. ; or it is dried, and then forms hay. The 

 I I 



