116 CHLOROPHYLL. 



isolated from the leaves of dicotyledonous plants a crystalline 

 chlorophyll, 1 which Hoppe-Seyler suspects to be a mixture of 

 erythrophyll, chlorophyllan and wax. Gautier's analyses agree 

 tolerably well with fhose of Hoppe-Seyler's chlorophyllan. 



135. Xanthoplmjll (phylloxanthin), the yellow colouring matter 

 to which the autumnal tint of many leaves is ascribed, appears to 

 be insoluble in water, sparingly soluble in cold ether, petroleum 

 spirit, or benzene. Alcohol dissolves it more readily, and it is 

 soluble also in ether-alcohol. It may be obtained as a yellow 

 granular deposit contaminated with fatty matter by evaporat- 

 ing an alcoholic extract (Berzelius). Dilute acid and dilute 

 potash and ammonia are said to dissolve it but sparingly ; the 

 latter may, therefore, be employed to effect a partial separation 

 from fat, etc. Sulphuric and hydrochloric acids colour it only 

 faintly blue. If the alcoholic extract has been shaken with 

 benzene, as directed in 132, the residue obtained on evaporating 

 the benzene solution may be purified by suitable treatment with 

 the foregoing liquids, especially petroleum spirit. 2 Hartsen thinks 

 that his chrysophyll is possibly identical with phylloxanthin. 



Hypoclilorin. Pringsheim 3 states that hypochlorin separates 

 from the chlorophyll granules in the form of yellow drops, which 

 gradually become crystalline. It is insoluble in water, dilute 

 acids and solutions of salts, but is easily dissolved by ether, 

 benzene, bisulphide of carbon and ethereal oils. In concentrated 

 and dilute alcohol it is at one time easily, at another difficultly, 

 soluble. Possibly it is volatile with the vapour of water. 



It would be premature, on the basis of the facts that have as 

 yet been established, to assert the identity of hypochlorin with 

 xanthophyll ; the latter is certainly not identical with etiolin, the 

 yellow colouring matter of etiolated plants, which in alcoholic 

 solution assumes a green tinge, and, after the lapse of some time, 

 is coloured blue by hydrochloric acid. 



for the colouring matter of certain Algae, see Sachsse, ' Chem. und Phys. d. 

 Farbstoffe, Kohlehydrate und Proteinsubstanzen,' Leipzig, 1877. 



1 Bulletin de la Soc. Chim. xxviii. 147, 1879 (Journ. Chem. Soc, xxxviii. 

 266). 



2 For the relation that xanthophyll (etiolin) bears to chlorophyll, see 

 Wiesner, Annal. d. Phys. und Chem. cliii. 622, 1874, and Chem. Centralblatt, 

 353, 1874 ; also ' Die Enstehung d. Chlorophyll's in der Pflanze,' Wien, 

 Holder, 1874. 



3 Chem. Centralblatt, 9, 27, 299, 316, 331, 1880. Compare also Jahresb. 

 f. Wissensch. Bot. 1874. See Quarterly Journ. Mic. Soc. 1881. 



