279 



solvent, the product had the opposite direction ofrotatioiitotli.it 

 of the original substance; whereas if aceto-nitrilc \\ n th. -<.1\ in . 

 the resulting aww/o-drrivative showed a rotation of tin- >ume kind 

 as before. 



Later a dozen optically active solvents \\vn- in d in 



this way, and the fact referred to above was plainly confirmed. 

 Si- nter concludes that it is becoming more and more evident 

 that a satisfactory explanation of the W a 1 d e n-inversion is not 

 likely to be reached at present, and that it must be consi'i 

 premature to enter now upon a full discussion of the significance 

 of the results obtained with respect to this highly interesting 

 phenomenon which, beyond all doubt, also plays an important 

 role in the chemical synthesis of the living ^organisms. 



5. Now we have to consider the two remaining cases : when 

 an optically active molecule acts upon an inactive one so as to 

 produce a new asymmetric carbon-atom in the already active 

 molecule, and the other case, when an optically active molecule 

 acts upon another optically active substance, or upon a substance 

 which is either externally compensated or racemic. 



Indeed, among these reactions we can safely include those, 

 where an optically active substance also acts upon a racemic or 

 an externally compensated substance. For as racemic compounds 

 in solutions are at any rate dissociated to a large extent, or even 

 totally, into their optical antipodes, and as inactive mixtures will 

 of course only act therefore as if their right and lefthanded 

 components were completely free, - - the action of such inactive, 

 resolvable substances upon optically active ones thus belongs here, 

 and not among the cases dealt with in the preceding paragraphs. 



In the first place we may remark that in general the affinity- 

 constants of two antipodes A and A' with respect to another 

 substance B, appear to be the same in all cases, even if B itself 

 is an optically active compound. In the last case, however, there 

 will be a certain difference of reaction-velocities, because the products 

 formed are no longer mirror-images of each other. The speed with 

 which AB is formed, need not be the same as when AB' is 

 produced. x ) 



Therefore, if an optically active compound B acts upon a 

 racemic or externally compensated substance A A' (or A + A'), 



1) Of course, the fact that the affinities are the same between A and B, and 



