ALCOHOLIC FERMENTS. 169 



II. Only one species (Monilia Candida) ferments maltose, 

 dextrose, and saccharose without, however, possessing 

 any inverting enzyme soluble in water. 



The lactose-fermenting Saccharomycetes and Torula occupy a 

 separate position. 



From the above it is clear that, as HANSEN asserts, the 

 Saccharomycetes cannot be characterised merely as alcoholic 

 ferments. 



When we consider the behaviour of these fungi in the 

 fermentation industries, it is at once seen that it is only 

 amongst the Saccharomycetes that species occur which rapidly 

 and vigorously ferment maltose. The yeasts for breweries and 

 distilleries must therefore be looked for from among the true 

 Saccharomycetes. The fungi excluded from the genus Saccharo- 

 mycetes, of which by far the greater number do not ferment 

 maltose, are scarcely capable of playing any important part 

 in these industries ; on the other hand they may be employed 

 in the manufacture of wines from grapes, berries, and fruits, 

 since several of them are able to induce just as vigorous a 

 fermentation in solutions of dextrose and invert-sugar, as the 

 Saccharomycetes. 



It is, then, of the utmost importance that a suitalle species 

 should he selected. 



These different properties of the various species of budding- 

 fungi are of special importance in analytical chemistry, in 

 cases where solutions containing several different carbohydrates 

 are under examination. In fact HANSEN has expressed the 

 opinion that it will be possible in this way to arrive at a more 

 exact quantitative determination of the different carbohydrates 

 in wort. Several chemists have been recently engaged on this 

 problem, but a true solution has not yet been effected. 



The characterisation of the synthetically prepared isomaltose 

 furnishes a fine example of the application of biological 

 analysis. As is well known, EMIL FISCHER discovered this 

 sugar species in the products of the reaction of hydrochloric 

 acid on grape sugar, at a low temperature, and it received the 

 name of isomaltose, because it appeared to have a constitution 

 similar to that of maltose. The sugar has not yet been 

 prepared in a state of purity, but is known only in the form of 



