340 THE BELL SYSTEM TECHNICAL JOVRXAL. MARCH 1952 



90,000 



1 2 4 6 i: 



00,000 



-: 100 400 looo io,cc: 



FP.z;_5:.CY IN KILOCYCLES PER SECOND 



Fig. IS — Frequency dependence of shear stiffne^ of 1 per cent solutions of 

 polj'isobutylene in cyclohexane at 25"C. 



Fig. 19 — Schematic diagram of possible sources of rigidity of single chain 

 molecules in solution. 



