THE SPACE RELATIONS OF ATOMS. 457 



between the two isomers which may be supposed to cor- 

 respond to the difference in the attractions X — R and 

 Y— R. 



A stereochemical formula for the carbon nitrogen com- 

 pounds in question is obtained by Van't HofT by joining the 

 nitrogen triangle to the carbon tetrahedron as shown in 

 figure 12. 



Fig. 12. 



Here R is represented in the position it would have if 

 X and Y were identical ; when they differ, one or the other 

 isomer results according as R approaches X or Y. There 

 is no evidence to show whether N is or is not attracted to 

 the same side as R. 



For the three benzil dioximes Hantzsch and Werner 

 give the formulae 



xc— CX XC— CX XC — ex 



II II II II II II 



RN NR RNRN NRRN 



Anti-dioxime. Amphi-dioxime. Syn-dioxime. 



In most cases these chemists have been able by a study of 

 the reactions of the isomers to determine which of the for- 

 mulae belongs to each. For instance, of the two formulae 

 R— C— H RCH 



II (syn-aldoxime) and II (anti-aldoxime), the 



N.OH HON 



