M. Wheldale 



371 



When heated with alkali, the various pigments split up, as in the 

 case of flavones, into a phenol and an oxybenzoic acid, which were 

 identified in each case : 



Cyanidin gave phloroglucin and protocatechuic acid. 



Pelargonidin „ „ „ jo-oxybenzoic 



Delphinidin „ „ „ gallic acid (not isolated in pure 



state). 



On the basis of the above decompositions and analyses (by combus- 

 tion) Willstatter first suggests the following alternative constitutional 

 formulae for three of the pigment salts : 



OCl 



v/\/ 



HO 



OH 



OH 



or 



HO 



OCl 



HO T 



OH 



Cvanidin chloride. 



\/0" II. 

 OH 



OCl 



HO 



or 



OCl 

 HoXV^ 



HO 



OH 



II. 



OH 



24—3 



