652 



^ 



o 



2.0 

 1.8 

 1.6 

 1.4 

 1.2 

 1.0 

 0.8 



3.2 

 3.Ü 



2.8 

 2.6 

 2.4 

 2.2 



2.0 



^ 1.8 



: 1.6 



•C 1.4 



o 



^ 1.2 



1.0 



0.8 



0.6 



16 18 2000 22 24 26 28 3000 32 34 36 38 4000 42 

 Reciprocal wavelengths. 



Fig. II. 12. Picrylphenyimethylamide (y. & |3). 13. id. + KOH. 14. PicrylmeÜiyl- 

 amide in sulphuric acid. 15. Picrylraethylamide. 



