754 



OH O 



R— C— O— C— R 



OH 



An objection to this formula is that two iijdroxjl-groups are 

 found at one C-atom which is not possible because water would 

 then be readily split off. 



The following formula appears to me to agree better with the 

 data. As is well-known alcohols have the power to form large 

 molecular compounds in the said solvents but only in concentrated 

 solutions, whereas the dilute solution contains single molecules. 

 Hence, we must assume that, in the acids, two causes are at work, 

 which by themselves ai-e not capable of producing the effect, namely 

 the hydroxyl- and the CO-groups. 



As the manner in which the OH-groups react on each other 



cannot be properly represented in the formula as yet, the double 



molecule might bo represented as follows: 



/OHHO. 



/ \ 

 R-c < Q > C-R. 



F'or our purpose, however, it is for the moment of less importance 

 what idea one entertains as to the double molecule: it is certain, 

 however, that in the case of acids we generally notice that they 

 combine by means of their carboxjd-groups. 



In the case of acids possessing two bonds in their molecule it is 

 very probable that on the transition of the licjuid state into the solid 

 one, the attraction of the two bonds may direct the molecules. 



Supposing the difference between a- and ^-cinnatnic acid to consist 

 solely in a difference of position of the double molecules in the 

 "Raumgitfer" we might then arrive to the following schema which 

 elucidates the transformation of the acids into a- and ,J-truxillic acid. 



a 

 ,0HH0 



C„H,CH=CH-C<[-]>C-CH=CHC,H, 



.OHHO. .OHHO. 



CeH,-CH=CH-C < > 0-CH=CH-C,H3C,H3-CH=CH-C < q > C-CH=CH-C,H, 



.OHHO. 

 C,H,CH=CH— C < > CJ— CH=CHC,H, 



