Tort] CURRENT LITERATURE 237 
up individually. The first series of experiments relating to the ratio of carbon 
dioxid to sugar fermented in the presence of excess of phosphates shows that the 
ratio agrees with that derived from the reaction formula given by the authors, 
that is, 2CsH,,0s—>2CO,, for the period of accelerated fermentation that 
follows the addition of phosphates to a fermenting mixture. i 
The question as to the necessity of phosphates for alcoholic fermentation 
is also taken up. While it has never been conclusively shown that alcoholic 
fermentation cannot. take place in the absence of phosphates, the experiments 
here given furnish strong evidence in favor of the view that phosphates are 
necessary for alcoholic fermentation. The authors reduced the quantity of 
phosphates in fermenting mixtures to a minimum, and found that the addition 
of very small quantities of phosphates to such mixtures increased the evolu- 
tion of carbon dioxid as much as 700 per cent of the original amount; while 
if no precaution is taken to remove the phosphates from the mixture at first, 
further addition of phosphates gives an increase of only ro—150 per cent of the 
original. The relatively large increase in fermentation due to the addition 
of small quantities of phosphates is regarded as strong evidence that phosphates 
are necessary in fermentation. : 
It is further shown that the hexose-phosphate when hydrolyzed by the 
enzymes of yeast juice yields a sugar which is fermented by living yeast, a 
result which is opposed to the conclusion of IWANOFF mentioned above. e 
Sugar thus obtained gives the reactions of fructose, although the possibility 
that other hexoses may be present is not excluded. 
Putting the facts thus far gained into the shape of a tentative theory, 
HARDEN and YounG suggest that two molecules of hexose may be decom 
into smaller groups, two of which go to form alcohol and carbon dioxid. The 
other two residues are synthesized into a new chain of six carbon atoms, which 
forms the carbohydrate part of the hexose-phosphate. 
Papers taking up the question of fermentation from a different viewpoint 
have been published by Kout and by Kusserow. Kout’s’ work relates 
chiefly to the part played by the enzymes in the different steps of fermentation. 
As far as the steps by which sugar is transformed into alcohol are concerned, 
he adheres to the original view of BucHNER that lactic acid is an intermediate 
Product. BucHNer attributes the first step in this process to the action of 
an enzyme which he called zymase, and which is not easily extracted from the 
cells by the usual solvents for enzymes. Kont finds that none of the enzymes 
extracted from yeast by glycerin or water are capable of transforming lactic 
acid into alcohol and carbon dioxid. It is therefore this step, he reasons, and 
not the changing of sugar into lactic acid, which must be attributed to the 
action of zymase. This leaves the splitting of lactic acid into alcohol and 
carbon dioxid to be accomplished by some of the soluble enzymes of the yeast 
a 
*Kont, F. G., Ueber das Wesen der Alkoholgirung. Beih. Bot. Centralbl. 
I. 25:115~126. roto. 
