227 



invertase are life-less chemical substances, the view that the special 

 phenomena of fermentation are not directly connected with the 

 life-process itself, but can be produced by such characteristic 

 substances present in the cells, has now become certain. 



Fischer l ) confirmed that ct-methyl-glycoside is decomposed by 

 invertase, while @-methyl-glycoside is not; with emulsine, however, just 

 the reverse occurs. The enzyme has thus undoubtedly a "selective" 

 action, in the same way as this was formerly stated in the case of 

 living organisms. This apparently selective action must most 

 probably also be referred to a great difference in the velocity of 

 action, when several enzymes are made use of for the attack of 

 the same kind of substances. 



Dakin 2 ) found that /^//-handed benzyl-mandelic ether is much 

 more rapidly hydrolysed by lipase (from the liver), than the dextro- 

 gyratory antipode, and that in general the ethers of optically active 

 acids are, in both enantiomorphous configurations, decomposed by it 

 with very differing velocities ; the differences in velocity can amount 

 to 50% and 130% of the values observed in the case of the other 

 antipode. 



Herzog and Meier 3 ) stated that mould-cultures, after being 

 killed by means of acetone er methyl-alcohol, will oxidize dextro- 

 gyratory tartaric acid much more rapidly than the laevo gyratory 

 isomeride, and the same appeared to be the case with other oxy- 

 acids, although not to so high a degree. A similar difference in velocity 

 of attack was found by Abderhalden and Pringsheim, 4 ) if the 

 juice of pressed cells of Aspergillus Wentii or of Allescheria Gayoni 

 were used for the decomposition of polypeptides, like leucylglycine, 

 into their optically active forms. After this, it can hardly be doubted 

 any longer that as a matter of fact a common explanation of the 

 "specific" attack of living organisms or of enzymes can be 



1) E. Fischer, Ber. d. d. Chem. Ges., 27, 2985, 3230, 3479, (1894); 28, 1429, 

 1508, 3031, (1895). 



2) H. D. Dakin, Journ. of Physiol., 30, 352, (1904); 32, 199, (1905); cf. also: 

 A. MacKenzie and A. Harden, Proceed. Chem. Soc. London, 19, 48, (1903). 



3 ) R. O. Herzog and A. Meier, Zeits. f. physiol. Chem., 59, 57, (1909). 



*) E. Abderhalden and H. Pringsheim, Zeits. f. physiol. Chem., 59, 249, 

 (1909); 65, 180, (1910); cf. also: G. Bredig and K. Fajans, Ber. d. d. Chem. Ges., 

 41, 752, (1908); and about the dependance of the fermentative action of yeast 

 on its feeding either with definite amtno-acids, or with other nitrogen-compounds 

 (naphtionic acid, metanilic acid, etc.), cf. : H. Pringsheim, Ber. d. d. Chem. Ges., 

 39, 4048, (1906); Biochem. Zeits., 3, 121, (1907). 



