APPENDIX 219 



(10 %) is added, and the pelargonin chloride is precipitated. The 

 crystallised product gives, on hydrolysis with hydrochloric acid, as 

 previously mentioned, pelargonidin and two molecules of dextrose. 



The flower-pigment of Delphinium (Willstatter & Mieg, 641). The 

 dried and powdered flowers are extracted with aqueous alcoholic hydro- 

 chloric acid. To the extract ether is added, thereby precipitating 

 impure delphinin chloride, which is then purified by further treatment 

 with methyl and ethyl alcohols and ether. The amorphous delphinin 

 chloride is finally again precipitated by concentrated hydrochloric 

 acid, and it does not readily crystallise. It is hydrolysed by water 

 with the precipitation of the violet base. With hot, moderately con- 

 centrated hydrochloric acid it is hydrolysed into two molecules of 

 dextrose, two molecules of jo-oxybenzoic acid, and delphinidin chloride. 



The pigment of grapes (Willstatter & Zollinger, 645). The method 

 of extraction in general has already been described (p. 77). Oenidin 

 contains two methoxyl groups, and is converted into delphinidin by 

 hydriodic acid and acetic anhydride. 



The pigment from fruits of the Bilberry, Vaccinium Myrtillus (Will- 

 statter & Zollinger, 645). The general method of extraction has been 

 described (p. 77). Myrtillin, on hydrolysis, gives myrtillidin and a 

 sugar which apparently has not yet been identified. Myrtillidin 

 contains only one methoxyl group, and gives delphinidin in the Zeisel 

 reaction. 



The flower-pigment of the Hollyhock, Althaea rosea (Willstatter & 

 Martin, 640). The dried and powdered flowers are digested with 

 methyl-alcohol-hydrochloric acid, and ether is added to the extract, 

 which precipitates the pigment althaei'n as chloride. The methods 

 for purification of the crude product have not yet been devised. On 

 hydrolysis with boiling, moderately concentrated hydrochloric acid 

 althae'in yields myrtillidin and one molecule of (?) dextrose. 



The flower-pigment of the Mallow, Malva sylvestris (Willstatter & 

 Mieg, 642). The dried and powdered flowers are digested with methyl- 

 alcohol-hydrochloric acid (2 %) and about ^ of the volume of con- 

 centrated hydrochloric acid, and the extract is precipitated with ether. 

 The precipitate, after some purification, is warmed with aqueous picric 

 acid (1-5 %). The pigment malvin crystallises out as picrate, and 

 is converted into chloride by treatment with methyl-alcohol-hydro- 

 chloric acid. Malvin yields, on hydrolysis with boiling 20 % hydrochloric 

 acid, malvidin and two molecules of dextrose ; it contains two methoxyl 

 groups, and yields delphinidin in the Zeisel reaction. 



