314 



acid was lessened to half its amount in 107 minutes, whereas the 

 laevogyratory acid dwindled to half its original concentration in 

 157 minutes. 



The speed of the reaction of the inactive acid is intermediate 

 between the values obtained for the optically active components; 

 it is difficult to say whether or not it may be concluded from 

 the data, that there is still some racemized acid really existent in 

 the solution, or that it is completely dissociated into its components. 



In the case of the bromo-campho-carboxylic acids, the right-handed 

 antipode is decomposed more rapidly, when quinidine is the catalyst, 

 whereas the left-handed antipode is on the contrary more readily 

 split up when quinine is present in the solution. 



If the decomposition be stopped before complete fission of the 

 acid has been reached, the inactive acid originally used will show 

 an optical activity. 



When quinine was used as catalyst in acetophenone as a solvent, 

 the portion of the acid not yet decomposed had become dextro- 

 gyratory (an excess of 14% of the d-acid being present after a 

 heating for 168 minutes), while the camphor produced in this 

 reaction was tewgyratory. But if under the same circumstances 

 (75 C.) quinidine were used as catalyst, the unattacked acid 

 had after 186 minutes of heating become laevogyratory , while 

 the camphor appeared to be ^^rogyratory. 



In these experiments the active bases are neither comsumed in a 

 detectable quantity, nor does there exist a stoechiometrical relation 

 between the quantities of the bases added and that of the acid 

 attacked; there is merely an accelerating influence, so that the func- 

 tion is absolutely comparable with that of organic enzymes or ferments. 

 Indeed, here we have to deal with the complete analog of the 

 action of the organic catalysts, and their remarkable "specificity". 



Bredig and Fiske treated benzaldehyde with HCN in the 

 presence of l-quinine or d-quinidine] the reaction took place in 

 chloroform as solvent. The base was removed by extracting the 

 solution by shaking it with 4-normal sulphuric acid, and the 

 mandelic acid thus obtained, when tested, appeared to be in reality 

 optically active. If the towgyratory quinine were used as a 

 catalyst, the acid was t^drogyratory, whereas with the dextrogyr&tory 

 quinidine, it was found to be laevogyratory. These facts remove 

 all doubt as to the fact that the remaining traces of adhering 

 base cannot be the cause here of the optical activity observed. 



