MOLECULAR ARCHITECTURE 707 



The general similarity of the dimensions is very noticeable in 

 all the above compounds and the accord of the symmetry with 

 one or other of the three assemblages described ; this bears out 

 the hypothesis that the hydrogen and halogen spheres of influ- 

 ence have approximately equal volumes in all these compounds. 



Similar facts have been established through the examination 

 of a large number of halogen-substituted benzene-sulphonic 

 chlorides and bromides. Some thirty of these compounds 

 have been examined in Professor Armstrong's laboratory and 

 the present writers have been able to show that the majority 

 possess the same general crystalline structure whatever be 

 the position of the halogen atoms in the nucleus. Most of 

 them exhibit rhombohedral marshalling, a few are pseudo- 

 cubic, a few rhombic. Not infrequently the connection between 

 the different series of compounds is not immediately obvious 

 from inspection of the axial ratios but when the parameters 

 are calculated, according to the rules already given, the close 

 relationship becomes obvious ; typical examples of such cases 

 are included in the following table : 



Cl 

 CI 



'0 



1-633:1:1-154 I05°2' fa 5-786:2-363:2-727 



SOjCl 

 Br 



Br 6 



II. I I 1-280:1:0-576 104V - 5960 : 2324 : 2-678 



2 



S0.,C1 

 Cl 



III. I J 0-813 : I : 0-569 90V 2a, 2c 5-731 : 2-349 : 2-675 



SOjCl 

 Br 



IV. 2-476:1:1-144 95°26' — 5-787:2-337:2-674 



SO.Cl 

 Br 



