212 



REPORT— 1901. 



The method employed in photographing the spectra has already been 

 described.^ 



It will be seen from the accompanying curves that the relation 

 existing between the two bodies is similar to that which exists between 

 Knorr's a- and /3-dibenzoylsuccinic esters. Both the substances show 



Curves of Molecular Vibrations. — Dibenzoylmethane, Ketonic, 

 o-Oxybenzalacetophenone (o-Hydroxybenzylidene aceto- 

 phenone), Enolic. 



well marked absorption bands, and the amount of general absorption 

 caused by the enolic form is, as in the case of Knorr's esters, considerably 

 greater than that caused by the keto form. In this case the gradual 

 change of the less stable into the more stable form has been traced by 

 photographing the acidified solution at intervals. 



» Trans. Chem. Sac, 1885, 47, 685. 



