110 



The Philippitie Journal of Science 



1914 



dredth molar concentration produced an absorption band in 



the color region heading at - = 2070. Two ultra-violet bands 



1 1 



at - = 3060 and - = 3480 show with low concentration. 



A A. 



The absorption spectrum obtained with concentrated sul- 

 phuric acid as the solvent no longer contains the color band, 



Oscillation frequency. 

 /a 2000 22 2* 26 2S 3000 3.Z J« 36 33 4000 « 



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Fig. 2. Full curve. Dithiophthalimide in alcohol. Dash-dot curve. Dithiophthalimide in alcohol 

 with 5 equivalentes of sodium ethoxide. Dash curve. Dithiophthalimide in sulphuric acid. 

 Dot curve. Dithiophthalimide in pyridine. 



but owes its reddish yellow color to general absorption. The 

 ultra-violet bands are still present, heading at the same points 

 as with acetic acid solvent, but the persistence of the one at 



= 3060 is greatly reduced (fig. 3), 



