272 PRESENT POSITION OF PURE YEAST CULTURE. 



certain species of bacteria which occur in Havanna and other 

 superior kinds of tobacco. Suchsland employs a mixture of 

 several species for this purpose. In the case of certain fer- 

 mentations in the dairy, the co-operation of several species 

 also appears to be necessary. In all cases in whick the fer- 

 mentation can be carried out with a single species^ as in the 

 brewing industry, this method is naturally to be preferred as 

 the simplest and most certain. 



There is no doubt that other branches of industry more or 

 less dependent upon a bacterial fermentation will follow suite 

 in deriving advantage from the new advance. It is strange 

 that in the manufacture of vinegar no step has yet been taken 

 in this direction. 



Nowadays it must be clear to every zymotechnologist 

 who has made himself familiar with the results of recent 

 investigation, that wherever fermentation organisms are made 

 use of, the aim must be the same, namely, to give up the old 

 traditional method which depended upon mere chance. In 

 this entire field a new era has now commenced. 



