of the Process of Fermentation. 1 65 



organs and tissues fitted for them, but the abnormal processes 

 of development of the embryonal cells contained in the tissue- 

 cells, called forth hj physico-chemical agencies, in the presence 

 of sufiicient quantities of grape-sugar or other bodies, cor- 

 responding with other processes of fermentation and decom- 

 position. Alcoholic fermentation, therefore, like the other 

 processes of fermentation and decomposition, has its foundation 

 in the necrobiosis of the organs and tissues in question. 



The fruits are suffocated in the oxygen gas, and in the other 

 gases employed, just as they are killed in every pure gas, in 

 water free from air, by mechanical injuries, &c. ; the normal 

 process of matui-ation is interrupted, in consequence of which, 

 and the presence of sugar in their cell-fluid, the cellules con- 

 tained in the latter or their endogenous new formations 

 acquire the nature of yeast-cells. In tigs and grapes this may 

 be recognized* very easily even from the form of the yeast- 

 cells thus produced ; whilst in plums, as in the gooseberries 

 Avhich I employed formerly (see ' Botanische Zeitung,' 1848) 

 in experiments on fermentation in hydrogen gas, the newly 

 formed cells acquire a globular form. 



Even here it is proved that the kind of biological process 

 of the cell-generations which develop themselves within dying 

 tissue-cells is dependent upon the chemical nature of the cell- 

 fluid and the matter and forces acting from without. The 

 Vibrios and Bacteria do not originate putrefaction, nor does 

 yeast originate fermentation, but rather the forms Avhich the 

 cells acquire are determined by the nature of the nutritive 

 material. If the fluids are predominantly albuminous, putre- 

 faction ensues with Bacteria and Vibrios ; if they are saccha- 

 rine, fermentation takes place with yeast, as I have demon- 

 strated in my ' Faulniss und Ansteckung ' (1872, p. 2). Nay, 

 according to the diflierent chemical nature of the fluids, varia- 

 tions of these processes will occur, presenting in their course 

 the greatest similarity to the biological processes of normally 

 assimilating secretion-cells. But in reality these morbidly 

 developed cell-generations are completely difierent in their 

 nature from the latter. 



* la figs we may most easily con-s-ince ourselves of the production of 

 yeast^cells within the tissue-cells during the sojourn of the fruit in car- 

 Donic acid, if we add to the microscopic section of such a fruit a portion 

 of a solution of cane-sugar or sugar of milk, and then observe it for some 

 time. This object may be cemented down like a microscopical prepara- 

 tion ; and it then slowly but surely shows the gi-owth of the yeast-cells. 

 Figs which had lain for eight weeks in carbonic acid without sliowing any 

 signs of mould or changing much in form and colour, but which had a 

 vinous-acid odour, were especially fitted to exhibit this development of 

 the grape-sugar yeast. 



