23 



When by accident leaves are too much moistened before they are 

 subjected to the sweating, they will soon lose their coherence and 

 show spots and finally holes. The water content, the writer found, in 

 one such case amounted to 06 per cent. Here, then, is a true action of 

 bacteria, which can develop under these conditions, as the high i)er- 

 centage of water admits an abundant exit of organic compounds from 

 the interior of the cells to the surface and the formation of a diluted 

 solution. Xow. it is the experience of every tobacco manufacturer that 

 the product will invariably spoil when the water content is increased 

 to such a point as to permit an exit of soluble organic compounds from 

 the cells. Here. then, begins the parallelism to the fermentation of 

 sauerkraut or ensilage, but not before. The objection that certain 

 kinds of thermophyhc bacteria might be capable of develoi^ing on the 

 leaves in the jiresence of a smaller ])ercentage of water can not be sus- 

 tained, as they require liquid food as well.^ And how will they reach 

 the interior f»f the cells without earing through the cellular walls, that 

 is. without ruining the product ? The claim that it is not the bacteria 

 but the enzyms they produce that enter can not hold good, as the 

 latter must be dissolved before they can migrate into the interior of 

 the cells, and hence a water increase is again required. The conclu- 

 sion that must invariably be reached, therefore, is that the bacteria 

 found ui>on the fermenting tobacco leaves do not participate in any 

 way in the fermentation i>rocess, but that they are accidentally pres- 

 ent and probabh' only in the form of spores. 



THE OXIDIZING AGENCY IN THE FERMENTING TOBACCO LEAF. 



After showing that the bacterial theory of Suchsland is erroneous, 

 as there exists no bacterial coating on the leaves, the question natu- 

 rally presents itself, what is the cause of the oxidizing action? The 

 assumi^tion of Xessler and of Schlosing that the contact with the 

 atmosjjheric oxygen would suffice can not be correct for the following 

 reasons: (1) The substances undergoing oxidation (tannin, nicotine, 

 etc.) do not show such powerful affinities for oxygen as to account for 

 the considerable development of heat: and (2) neither curing nor fer- 

 mentation sets in when the fresh leaves are killed by direct application 

 of steam, although those organic matters which become oxidized in the 

 fermentation process are not changed at all thereby. 



Neither the tannin nor the nicotine of the leaves can be energetically 

 oxidized by the molecuhir oxygen of the air without assistance or 

 stimulation of some sort. In the same way dilute alcohol can not be 

 oxidized into acetic acid by the common molecular oxygen of the air 

 except through the intervention of certain bacteria or i)latinum black.- 



1 Cohn made investigations on the growth of thermogenic micrococci in the refuse 

 from the cotton purifier. However, he had to add a fair percentage of Avater to 

 start the development. 



-Miiller-Thurgau declares (1. c, p. 508) that '-In the beginning of the curing the 

 changes consist in an increased respiratiou, but later on, after the cells have died, 

 in other ('andertceitigen') oxidation processes," but he gives no explanation of the 

 cause of these latter ones. 



