viii. a, 6 Pratt: Phthalides and Related Compounds 



403 



Oscillation frequency. 



3000 32 34 36 3d 4000 



4.8 



/. 1 



i 2.\ 













4.6 

















4.4 

















c 



1 42 

















CD 



u 



CO 



"3 

 £ 



1 4.0 

















«— 1 



o 



OQ 



I 3.8 

















£ 

 £ 



s 3.6 

















e 



1 3.4 

















CO 



"2 



«H 

 O 



« 













■ < 





00 



M 







►J 

















?8 















26 

































Fig. S. Curve 1. Maleic anhydride in glacial acetic acid. Curve t. Maleic anhydride 

 in sulphuric acid. 



