1885.] Enter ochlorophyll and Allied Pigments. 321 



chlorophyll. On doing this, I found that his statement to the effect 

 that chlorophyll is not decomposed by such treatment, is not supported 

 by the results obtained. The bands of solutions after saponifying 

 occur in an entirely different position from those of bands of similar 

 solutions before saponifying, but I found the method useful in 

 enabling me to compare the results when enterochlorophyll and 

 Spongilla chlorophyll are saponified with those obtained in the case of 

 plant chlorophyll. 



I could separate, in the case of plant chlorophyll, the constituents 

 called by Hansen " chlorophyll green" and "chlorophyll yellow," by 

 adopting his methods, and found that the soap on repeated extraction 

 with petroleum ether, lost all the yellow colouring matter, and that 

 the latter could be obtained in some cases in yellow needles,* the 

 residue giving the colour reactions of Schwalbe and Capranica. The 

 alcohol and ether extracts on the other hand contained Hansen's 

 " chlorophyll green," and none of the yellow constituent, and 

 answered, except for the position of its bands, to Hansen's description. 



On applying the same method to the chlorophyll of Spongilla, a 

 complete separation of the constituents could not be brought about, 

 as it was only partial, and an examination of the solutions showed a 

 total alteration of spectra. 



In the case of enterochlorophyll, saponification also alters the pig- 

 ment. In some cases I succeeded in separating the yellow from the 

 green constituent ; and from the enterochlorophyll of Uraster rubens, 

 I obtained crystals of " chlorophyll green " and " chlorophyll yellow," 

 the former crystallising in sphere crystals, showing a black cross with 

 polarised light, the latter in yellow radiating needles. But in almost 

 every case it was found impossible to separate the constituents, as the 

 petroleum ether showed a band in red, and the alcohol and ether bands 

 in the blue end of the spectrum. 



The solid chlorophyll yellow, while agreeing with that of plants in 

 its behaviour towards nitric and sulphuric acids, did not, however, 

 show the same blue-green colour with iodine in iodide of potassium, 

 as it generally became reddish or remained unchanged. 



I agree with Hansen that the chlorophyll yellow of plants is a 

 " lipochrome," and also that of enterochlorophyll ; the lipochromes 

 being a class of colouring matters — so-called by Krukenberg — which 

 were formerly known by the name of " luteins." Under this name 

 are also included allied pigments, such as carotin, zoonerythrin, 

 Kuhne's chromophans — obtained by him from the retina, egg-lutein, 

 and other pigments, which all possess bands in the blue and violet, 

 and are soluble in such solvents as alcohol, ether, chloroform, bisul- 

 phide of carbon, benzol, petroleum ether, &c. They all are coloured 



* It is aot yet clearly proved whether these yellow needles may not belong to a 

 fatty acid whose crystals are stained by the yellow colouring matter. 



