311 



synthesis of an inorganic molecule being performed here, wholly 

 analoguous to the cases dealt with above. 



Recently Weiss *) demonstrated that, when unsymmetrical 



phenyl-p-tolyl-ketene : r 6 ^ 5 ^ C ~ CO, is treated with l-menthol 



CHs-C^H^/ 



in absolute etherical solution, the addition-compound produced in 

 this case is exclusively the ^^rogyratory l-menthyl-phenyl-p-tolyl- 

 acetate. It seems, therefore, that under the prevailing conditions, 

 the directional influence of the pre-existing dissymmetry in the 

 laev ogyratory menthol is strong enough to prevent completely the 

 formation of the corresponding laevogyratory antipode. The pro- 

 perties of the racemic and optically active l-menthyl-phenyl-p-tolyl- 

 acetates were already formerly described by MacKenzie and 

 Wi d do ws 2 ), -their identification thus being much facilitated. 



10. From these experiments the correctness of the view is 

 proved beyond all doubt, that a pre-existing molecular dissymmetry 

 has a powerful guiding influence on the chemical synthesis in which 

 new asymmetric carbon-atoms are created. From this the one-sided 

 natural synthesis in plants and animals has not only become 

 conceivable, but the contrast between the natural synthesis by the 

 living organism and that by the chemist, as contended by vitalists, 

 has mostly vanished, since the one-sidedness of natural synthesis is 

 thus brought within the scope of chemical dynamics, it being now 

 reduced to a merely relative difference in react ion velocities. 



The important investigations on catalysis by B re dig 3 ) and 

 his pupils during the last eight years before the war, have cor- 

 roborated these ideas most thoroughly, since the analogy of 

 chemical catalysis and the action of organic enzymes and ferments 

 was absolutely demonstrated by them. 



It has been already repeatedly stated in the preceding pages 

 that ferment-, and enzyme-action is evidently not really a "specific" 

 one, but merely one differing quantitatively. Dak in found, that 

 benzyl-l-mandelate was decomposed by lipase (from the liver) about 



1) R. Weiss, Monatshefte fur Chemie, 40, 391, (1919). 



2) A. MacKenzie and S. T. Widdows, Journ. Chem. Soc. London, 

 107, 702, (1915). 



3) G. Bredig and R. W. Balcom, Ber. d. d. Chem. Ges., 41, 740, (1908); G. 

 Bredig and K. Fajans, ibid., p. 752, (1908); G. Bredig, Verb. d. naturwiss. 

 Verein Karlsruhe, 25, (1913); K. Fajans, Zeitschr., f. phys. Chemie, 78, 25, 

 (1910); G. Bredig and P. S. Fiske, Bioch. Zeits., 46, 7, (1912); H. J. M. 

 Creighton, Zeits. f. phys. Chemie, 81, 543, (1913). 



