CHAPTER V. 



Alcoholic Ferments. 



INTRODUCTION. 



IT -does not lie within the scope of a work of this descrip- 

 tion to give a detailed summary of the knowledge of bygone 

 times, and it will suffice to pass in review as much only as is 

 necessary for the proper understanding of the present position 

 of the subject under discussion. As the investigations of the 

 last decade originated essentially from questions connected 

 more or less directly with practice, the results obtained are 

 also fully entitled to a practical application. It is evident, 

 however, that this can only be brought about when the 

 essential results of these scientific investigations are 

 thoroughly appreciated ; and it is with the object of facili- 

 tating this that the following resume is given. 



The term alcoholic ferment, as commonly used, is very 

 comprehensive. Mould-fungi, as well as bacteria and budding- 

 fungi, are able to induce alcoholic fermentation ; but here we 

 have only to deal with the last-mentioned. Amongst these 

 budding-fungi are some which also develop mycelium, whilst 

 with others this form of growth does not as a rule occur ; 

 among these latter yet another group is included under the 

 name Saccharomycetes, on account of the property which its 

 members possess of forming endogenous spores. 



In the year 1839 Schwann found that in the case of 

 certain yeast cells new cells were formed in their interior, 

 and that these were liberated through the bursting of the 

 walls of the mother-cells. /. de Seynes (1868) was, 



