Contributions to the Chemistry of Chlorophyll. 307 



times its volume of alcohol and left to stand, when it deposits a great 

 part of the phylloxanthin, much of the fatty matter being left in 

 solution. 



The deposit is then filtered off, washed with alcohol, dried, and 

 dissolved in boiling glacial acetic acid. This solution on cooling 

 and standing yields a copious deposit of phylloxanthin, which is 

 filtered off and may again be dissolved in boiling glacial acetic acid. 

 The second deposit is filtered off, washed with alcohol, and dissolved 

 in hot ether. The ethereal solution is then slowly evaporated in 

 beakers. During evaporation a dark mass is deposited, which after 

 about three-fourths of the ether have evaporated is filtered off and 

 redissolved in ether. The ethereal solution is evaporated, and the 

 portion which first separates out is filtered off as before. This process 

 may be repeated several times if it is thought necessary. The quantity 

 finally obtained after this lengthy process is, of course, relatively 

 small. Unfortunately, too, it is after all not absolutely pure ; it 

 contains fatty matter, as may be easily ascertained by treating a little 

 of it with moderately strong boiling nitric acid, when the colouring 

 matter is decomposed and dissolved, leaving the fatty matter, which 

 floats about in the boiling liquid in oily drops. There is no reason, 

 however, to suppose that this contamination with fatty matter inter- 

 feres with the reactions of the substance, so far at least as its behaviour 

 to various solvents and the colour or changes of colour which it 

 presents are concerned. The properties of phylloxanthin resemble 

 those of phyllocyanin so closely as to lead to the conclusion that 

 the two substances must be closely related, that they are perhaps 

 isomeric, and that possibly one of them might be converted into the 

 other by some process still to be discovered. In the following descrip- 

 tion, therefore, I shall refer only slightly to those properties which 

 the two substances possess in common. 



When prepared in the way above described and then dried phyllo- 

 xanthin appears dark green, almost black, thus differing from phyllo- 

 cyanin, which always shows a dark indigo-blue colour. It is 

 amorphous, even under the microscope, though it may occasionally be 

 obtained by very slow evaporation of its ethereal solution in small 

 rosettes, which are rust- coloured by transmitted light. When a very 

 minute portion is placed on a glass slide, then moistened with ether 

 under a cover-glass, it is seen to resolve itself under the microscope 

 into a number of long whip-like filaments and pseudo-crystalline 

 needles, much curved and twisted, which are brown by transmitted 

 light. Chlorophyllan, according to Hoppe-Seyler, shows the same 

 behaviour under the microscope. 



Phylloxanthin is soluble in boiling absolute alcohol, but a great 

 part separates out again on the solution cooling as a granular 

 amorphous deposit. It is more soluble in ether, carbon disnlphide, 



