Miss Wheldale, On the nature of anthocyanin. 155 



throw more light upon this point. In connection with the 

 statement, that in genera showing various reds and purples, 

 i.e. Phlox, Lathyrus, Dianthus and Matthiola, the ultimate purple 

 variety contains an anthocyanin giving a blue iron-reaction, it is 

 of interest to mention the fact that this ultimate purple anthocyanin 

 can often be differentiated into a redder portion (though not 

 identical with the anthocyanin of the reds), soluble in alcohol, and 

 a bluer portion insoluble in alcohol, but readily soluble in water. 



All cases have not been thoroughly investigated, but as far 

 as they go the results point to the conclusion that the bluer 

 portion gives a blue precipitate with basic lead acetate, a blue 

 colouration with alkalis, and a blue colour with iron salts. 



The bluer portion predominates in berries of Samhiwus nigra 

 and Ligustrum vulgare, which give a blue colour with all the 

 above reagents. A more careful investigation was made of the 

 berries of Ligustrum. For this purpose the dried berries were 

 pounded and extracted with absolute alcohol. The alcohol extract 

 contained, in addition to chlorophyll, a crimson colouring matter, 

 which may be termed (A). When the alcohol ceased to be 

 coloured, the residue was dried again and then treated with water. 

 The filtrate was deep purple red and contained the greater part 

 of the colouring matter of the berries. The purple-red pigment 

 may be termed (B). The reactions of the two portions were 

 respectively as follows : 



This result is comparable to those obtained by the following 

 authors : — 



Grafe^^ isolated a colouring matter — Malvenfarbstoff — from 

 the flowers of Althaea rosea by precipitation of the extract with 

 lead acetate and subsequent decomposition with sulphuretted 

 hydrogen. The pigment was separated into two portions differing 

 in their solubilities, i.e. : — 



Colouring matter (A) Colouring matter (B) 



Soluble in alcohol Insoluble in alcohol but soluble in water 



C14H16O6 C20H30O13 



The author regards (B) as a di-basic acid; the relationship 

 between the two pigments is shown in the following equations : — 



C20H30O13 + H2O = CgHiaOg -I- ChHisOs, 

 glucoside 

 2ChH,80s - 2H,0 - O, - 2C,Ji,,0,. 



