306 Mr. E. Schunck. 



least when the process first described, using ether and hydrochloric 

 acid, was employed ; and it is this, following the example of Tschirch, 

 that I propose to call phylloxanthin in the stricter sense, inappropriate 

 as the term is in some respects. 



Phylloxanthin is a product formed along with phyllocyanin by the 

 action of strong acids on chlorophyll, and is left dissolved in ether 

 when to an ethereal solution of the two concentrated hydrochloric 

 acid is added, the phyllocyanin passing into the acid. When the 

 process described in the first part of this memoir, the first stage of 

 which consists in passing hydrochloric acid gas into an alcoholic 

 extract of leaves, is employed, the xanthophyll, chrysophyll, and any 

 other colouring matter that may be present remain in solntion, while 

 the phyllocyanin and phylloxanthin formed by the action of the acid 

 are deposited along with some fatty matter. 



Having thus explained the sense in which the terms phyllocyanin 

 and phylloxanthin are employed in this memoir, I will now proceed 

 to give an account of the mode of preparation and properties of 



PTiijlloxantliin. 



Although the quantity of this substance formed by the decomposi- 

 tion of chlorophyll with acids is mueh larger than that of tbe 

 phyllocyanin accompanying it, its preparation in a state of purity is 

 much more difficult, and the product even at the best is never free 

 from impurities of a fatty nature. 



The olive-green ethereal solution containing phylloxanthin, after 

 being separated from the lower acid one containing phyllocyanin, and 

 shaken up with concentrated hydrochloric acid, so as to remove any 

 of the latter substance that may be present, is left exposed to the air 

 in shallow vessels, so as to allow the greater part of the ether to 

 evaporate, when it leaves a quantity of matter in dark brown cakes 

 floating in an acid liquid. The latter having been removed, the 

 cakes are washed with water, and then left to drain on paper. That 

 the mass thus obtained contains, besides colouring matter, a large 

 quantity of fat is evident, for on rubbing a small portion between the 

 fingers it softens, and it melts completely in boiling water. The fatty 

 matter may, to a great extent, be removed by treating the mixture 

 with concentrated hydrochloric acid, in which the colouring matter 

 after a time dissolves leaving the fatty matter behind ; but the former 

 undergoes a change by this treatment, and is no longer unalterec 

 phylloxanthin, as I shall show further on. By the action of alkalis, 

 too, a change is effected, so that it is necessary to use other solvents 

 for the purification of phylloxanthin. For this purpose the crude 

 substance from the ethereal solution is first dissolved in a small 

 quantity of chloroform, and the solution is then mixed with several 



