196 



Mr. G. Currey. 



obtained was examined for the following properties, viz., crystalline form, 

 colour, and reflex ; colour changes on the addition of ferric chloride to 

 aqueous and alcoholic solutions ; colour of solutions in aqueous acid and 

 alcohol ; colour changes with alkalies ; behaviour with Fehling's solution (hot 

 and cold) ; colour of precipitate with lead acetate ; behaviour with sodium 

 bisulphite ; behaviour with zinc and dilute acid ; solubility in ethyl alcohol 

 at 19° C. ; solubility in aqueous hydrochloric acid (1 per cent, and l - 5 per 

 cent.) at 20° C. ; and the distribution of the pigment between amyl alcohol 

 and dilute aqueous acid. 



On comparing these properties with those given by Willstatter and Nolan 

 for cyanin chloride, they were found to be identical ; the anthocyan pigment 

 of the red rose " George Dickson " is, therefore, the di-glucoside cyanin. 



Hydrolysis of the Cyanin Chloride. 



The hydrolysis was carried out by boiling a small quantity of the glucoside 

 pigment with 20 per cent, hydrochloric acid for three minutes ; on standing, 

 the sugar-free pigment separated in small needles (not long ones, as obtained 

 by Willstatter), possessing a metallic lustre. On examination these were 

 found to possess the same properties as described by Willstatter and Everest 

 for cyanin chloride. 



Examination of the Yellow Sap-Pigment. 



The ether-alcohol liquor, decanted from the anthocyan precipitate, was 

 shaken with powdered calcium carbonate, and, after being allowed to stand 

 for a short time, filtered. The filtrate, which possessed a clear, deep yellow 

 colour, was concentrated to a small bulk and treated in the following 

 manner : — A portion was evaporated to dryness and the residue extracted 

 with ether ; the ether solution was washed with dilute hydrochloric acid, to 

 free it from traces of anthocyan pigment, filtered, and the filtrate shaken 

 with dilute sodium carbonate solution, which became yellow in colour. 

 Having shown that this alkaline solution contained the pigment in the form 

 of a glucoside, the remainder of the concentrate was poured into water and 

 boiled, to expel the small quantity of alcohol still present ; the aqueous 

 solution was then boiled with hydrochloric acid, to hydrolyse the glucoside 

 present, allowed to cool, and extracted with ether. The ether extract was 

 washed several times with aqueous acid, of different strengths, to ensure the 

 removal of traces of anthocyanidin, and finally filtered. The filtrate was 

 then shaken with dilute alkali, when the pigment passed into the alkaline 

 layer, which assumed a deep yellow colour (the absence of a green colour here 

 shows the absence of myricetin), which rapidly became dark brown on 



