THE FEBMENT OF MAUDEB ON SUGAB. 135 



decomposition appropriate to their respective production. 

 The alcoholic fermentation of sugar is also effected by 

 erythrozym, as I have shown.* 



But it still remains uncertain, and the point is one of con- 

 siderable interest, whether the formation of succinic acid from 

 sugar is a specific effect due to erythrozym alone, or is shared 

 by the latter in common with other ferments, such as yeast 

 and emulsine. On this point I have no evidence to offer, but 

 must content myself with a few general considerations, 

 leading to the conclusion, that it is not improbable that other 

 ferments will be found capable, under peculiar circumstances, 

 of producing this acid from sugar. 



The conversion of sugar into alcohol and carbonic acid, 

 and also that of sugar into butyric acid, carbonic acid, and 

 hydrogen, are well understood processes. In the former case 

 1 eq. of sugar splits up into 2 eq. of alcohol, and 4 eqs. of 

 carbonic acid. 



1 eq. Sugar. Alcohol. 



C.. H,, O,, = 2C^ H, O, + 4 C O, 



In the second case, 1 eq. of sugar splits up into 1 eq. of 

 butyric acid, 4 eqs. of carbonic acid, and 4 eqs. of hydrogen.f 



1 eq. Sugar. Butyric Acid. 



C,. H,. 0,a = Ca H, O^ + 4 C O, + 4 H 



But as regards succinic acid, it is difficult to indicate with 

 positive certainty in what manner it takes its rise from sugar, 

 because, in the fermentation of the latter with erythrozym, it 

 is evident that there are two processes going on side by side, 

 the one being the formation of alcohol, the other that of 



* It is possible that butyric acid may also be one of the products of tlie 

 action of erythrozym on sugar, though it is not probable, as among these pro> 

 ducts I have not been able to detect lactic acid, which constitutes the inter- 

 mediate stage between sugar and butyric acid. 



f I leave out of consideration the fact that sugar, before being decomposed, 

 in the manner mentioned, b first converted into lactic acid ; but this fact is of 

 no consequence as regards the result, since sugar and lactic acid have the same 

 percentary compoeitioo. 



