ARTICLES 



255 



many structural and optical isomerides are predicted; for 

 example, in the first we have the enantiomorphous isomerides 



8 



^ 



C Cy 



A A A 



B Bt Ud D, 7B 



D D z — r^D 



m,.cr vx£t 



K C z — r-'C 



c 



and also the " structural " isomerides (not enantiomorphous) 





VA 



Bodies of such a complicated structure either have not hitherto 

 been prepared or else their constitutions have not been suffi- 

 ciently established for these conclusions to be put to the test. 

 In more simple cases, however, also preceded by theory, it has 

 been possible to test the conclusions reached, since it is not 

 necessary for four or even three different groups to be present 

 so long as at least two pairs are connected, inasmuch as only 

 a different spatial orientation of the connecting chains is needed 

 to cause molecular enantiomorphism. 



The possibility of such isomerism when only one kind of 

 group is present is shown by the following figure and its mirror 

 image where, using the above conventional representation, the 

 connecting chains are represented by dotted lines ' : 



=cj 



1 The figures can be better appreciated if models are used. These may con- 

 veniently be made by cutting from large corks octahedra of about 2 cm. edge. 

 Small pins with glass heads or ordinary pins with heads covered by sealing-wax 

 variously coloured may be used to represent atoms or groups, while chains may 

 be represented by thin strips of stiff paper carried by pins stuck into the corks at 

 the angles. 



