ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 681 



Chlorophyllan is identical with the crystallized chlorophyll of 

 Gautier and Eogalski, the pure chlorophyll of Jodin, the precipitate 

 obtained by Filhol by the action of hydrochloric acid on solutions of 

 chlorophyll, the modified chlorophyll and acid chlorophyll of Stokes. 

 It can be reduced by means of powdered zinc to a pure green sub- 

 stance, probably identical with chlorophyll ; and this is the best way 

 of obtaining the pure chlorophyll-pigment. Sodium reduces it to the 

 pure green sodium-salt of chlorophyllinic acid. Chlorophyllan must 

 therefore be regarded as a product of oxidation of chlorophyll. Con- 

 centrated hydi'ochloric acid decomposes it into a substance soluble in 

 hydrochloric acid with a blue colour, the phyllocyanin of authors, 

 and a brown substance insoluble in hydrochloric but soluble in ether, 

 the xanthin of Kraus. Phylloxanthin is a mixture of the latter with 

 the normal yellow pigment of chlorophyll. The phyllocyaninic acid 

 of Fremy is probably identical with Hoppe-Seyler's chlorophyllanic 

 acid. Xanthin, when dissolved in alcohol, does not show the line IV. b. 



By treatment with potash-lye chlorophyll is converted into the 

 potassium-salt of chlorophyllanic acid, insoluble in benzin and ether. 

 The beautiful emerald-green solution can be precipitated by baryta 

 or copper-salt, with formation of the corresponding salts of chlorophyl- 

 linic acid. Alkaline carbonates also cause the formation of salts of 

 this acid. The spectrum of a solution of potassium chlorophyllinate 

 is distinguished by a splitting of a line in the red (into I. a and I. h), 

 and by the middle line being less distinct ; the lines are also all 

 displaced towards the refrangible end of the spectrum. The potas- 

 sium and barium salts of chlorophyllinic acid pass, with ether and 

 hydrochloric acid, into bodies belonging to the chlorophyllan-group ; 

 their spectrum has the line IV. h. Alkaline salts of chlorophyllinic 

 acid are formed when leaves are extracted with dilute potash-lye ; 

 when potash-lye is added to an alcoholic solution of chlorophyll ; 

 and as a precipitate when a solution of chlorophyll in benzin or a 

 solution of chlorophyllan is treated with sodium. When heated to 

 210° C. potassium chlorophyllinate assumes a purple-red colour. 

 This solution, when treated with hydrochloric acid and ether, yields 

 phyllopurpurinic acid, with a beautiful purple-red colour and a very 

 characteristic specti'um. 



From pure chlorophyll, the cyanophyll of Kraus, yellow sub- 

 stances or xanthophylis can be derived : — (1) by heating the solution 

 with baryta hydrate, and dissolving out by alcohol from the resulting 

 precipitate ; (2) by heating cyanophyll with sodium, when the xantho- 

 phylis can be retained in solution in benzin, sodium chlorophyllinate 

 being precipitated ; (3) by decomposing the cyanophyll by potash-lye, 

 evaporating, dissolving the potassium chlorophylliaate in water, and 

 the xanthophyll in ether. 



Yellow substances belonging to the chlorophyll group normally 

 accompany chlorophyll in the chlorophyll-grain. The yellow coloui-- 

 ing matter of flowers and the red colouring matter of flowers and 

 fruits mostly belong, as is shown by their spectrum, to the chloro- 

 phyll group. To this group belong also the colouring substance of 

 the carrot and radish, and that of green decaying wood, xylindein. 



