A certain amount of fermentation takes place 

 in the curing houses during the "yellowing" of 

 the leaf after it has been harvested, but as we 

 have seen the main process of fermentation does 

 not occur until it is "rehandled" by the manu- 

 facturers. 



The general opinion held at present as the 

 result of investigation is that the transforma- 

 tions which are effected in the leaf are purely 

 the result of chemical processes. As the plant 

 slowly dies and decomposes special ferments 

 are produced. These ferments set up an oxi- 

 dization process which splits up the complex 

 organic compounds which still exist in the leaf 

 cells. The starch in the plant is changed into 

 sugar which is slowly consumed. There is a de- 

 crease in the fats and gummy substances, also 

 in nicotine and nitrogenous compounds, and 

 there is a formation of certain organic acids 

 such as malic, citric and oxalic which are 

 essential in the production of flavor. Briefly it 

 may be said that the process is an attempt by 

 the plant to prolong its existence by feeding on 

 its own substance, by drawing on its own re- 

 serves and on its own structure for the food 

 which its cells no longer receive through the 

 natural growing process. When the struggle 

 is over the "fermentation" is complete. The 

 necessity for maturing tobacco has long been 



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