170 MICRO-ORGANISMS AND FERMENTATION. 



an osazone. C. J. LINTNER recently announced that he had 

 discovered isomaltose in beer, and he then described the 

 formation of the same sugar through the hydrolysis of starch. 

 BROWN and MORRIS, on the other hand, asserted that isomaltose 

 does not exist among the inversion products of starch, but that 

 the substance described by LINTNER as isomaltose is nothing 

 but maltose contaminated by dextrine-like decomposition pro- 

 ducts. LINTNER has hitherto not succeeded in adducing 

 fresh evidence in support of his view. Even the existence 

 of FISCHER'S synthetically formed isomaltose has been ques- 

 tioned, this substance being also regarded as impure maltose. 

 By a fresh investigation, however, FISCHER succeeded in 

 proving biologically that this sugar is sharply distinguished 

 from maltose by the fact that isomaltose is neither fermented by 

 fresh yeast nor decomposed by the enzymes of yeast, and he asserts 

 that it is only possible to differentiate with certainty between 

 the two sugar species in this way. 



The different action of the Saccharomyces species on the same 

 nutritive liquid (e.g, wort or must) under identical conditions, 

 has been further studied by BORGMANN, AMTHOR, and MARX. 



According to BORGMANN, the chemical reactions brought 

 about in wort by the two Carlsberg bottom-yeasts, No. 1 and 

 No. 2, show a striking difference. These two species which 

 had been in use for some time in the fermenting room, and 

 were still practically pure were employed for pitching two 

 fermenting vessels containing wort from the same brew ; the 

 fermentation took place under conditions which enabled a true 

 comparison to be made, and the resulting beer was stored 

 as usual. The differences in the products were especially 

 noticeable in the proportion of free acid. Thus : 



No. 1. No. 2. 



Acid (calculated as lactic acid), - 0'086 0'144 per 100 c.c. 



Glycerine, - - - 0-109 0'137 



As a result of these experiments, BORGMANN points out 

 that the ratio between the alcohol and glycerine in these 

 two beers differs from that previously found in beer, the ratio 

 obtained from previous analysis being : 



Alcohol. Glycerine. 



Maximum, - 100 5 '497 



Minimum, ------ 100 4-140 



