252 



Grouvelle that only in a certain region which lies between the outside • 

 surface and the middle of the heap is the fermentation relatively sa- 

 tisfactory. Belhomme has shewn the importance of the moisture contact 

 in the fermentation of snuff tobacco, even differences of 1 per cent, are 

 the cause of great difficulty and trouble in the fermentation. 



An important work by the elder Suchsland which treats of the che- 

 mistry of the fermentation of snuff- tobacco is said to prove that the 

 same consists in the combustion of the organic matter at the cost of the 

 atmospheric oxygen. Suchsland first of all sterilised a large quantity of 

 tobacco of one quality in separate vessels by keeping them for 1\ hours 

 at a temperature of 115 to 120 degs. C , and then forced in equal quan- 

 tities of air at an equal rate through all the vessels. Some of the ves- 

 sels were infected with fermenting snuff-tobacco and samples of each 

 were kept at temperatures between 40 and 70 degs. C. (104-158 F.) 

 The result of these experiments in Suchsland's own words is "that beyond 

 a' certain temperature not exactly defined, but above 40 degs. and below 

 70 degs. C, and probably about 50 degs. C. (122 degs. F..) the action 

 was a purely chemical one in which organisms took no part." Behrens 

 considers this as proved, provided always that the sterilisation had been 

 sufficient, which he thinks doubtful, as otherwise the strong fermenta- 

 tion which took place at 70 degs. C. might be due to the activity of 

 thermophile bacteria. 



Further experiments were performed with the fermentation of to- 

 bacco at high temperatures at 39, 70 and 80 degs. C, one result of which 

 was to shew that the purely chemical action (where the tobacco had 

 been previously sterilised) increased quickly with the temperature. 

 Even here the same objection, as in the previous case, holds good, viz. : 

 that the sterilisation had not been sufficient, and that even at 70 and 

 80 degs. C. thermophile bacteria had been active. Behrens considers 

 however, the i ext experiment to be quite free from objection. In this 

 case, the unsterilised tobacco was fermented at a temperature of 100 degs. 

 C. (212 degs F.) and developed in the unit of time far more carbon dioxide 

 than at 70 or 80 degs., and what was most important, exhibited all 

 the qualities of good snuff tobacco, the aim of fermentation was com- 

 pletely fulfilled and in much shorter time than at 70 or 80 degs. While 

 the tobacco fermented at 70 degs. took at least two months before it 

 was ripe, at 100 degs. it possessed all the physical and chemical pro- 

 perties of good snuff tobacco at the end of 10-12 days. 



According to Suchsland's idea then the rule of microbes in snuff to- 

 bacco fermentation was restricted to raising the temperature sufficiently 

 high to enable the chemical action to take place. 



