CHLOROPHYLLINE CHROMrLES. 117 



cases the material basis exhibits the more definite forms belonging to 

 true chlorophyll globules. 



Sometimes yellow-coloured drops occur in the cells, the chromule 

 being dissolved in an oleaginous substance, whilst cases have been ob- 

 served, but rarely, where the entire cell was filled with this liquid. 

 In some examples of this the author remarks how the liquid frequently 

 shows a changing hue, so as to make it doubtful sometimes whether 

 the cell is filled by a yellow or a green liquid. 



The optical qualities of this chromule in regard to its greater or 

 less approach to green chlorophyll is by no means in proportion to the 

 form of its basis. The chemical changes which the chromule itself 

 suffers cannot, however, on the whole, be very considerable, seeing 

 how slightly their optical characteristics vary. It might be assumed 

 that this close optical correspondence arose from the presence of un- 

 changed chlorophyll in the yellow blossoms employed. This, however, 

 cannot in any way be anatomically demonstrated, and it h impossible, 

 after the manner of the attempted separation of chlorophyll, to sepa- 

 rate the anthoxanthin (possessing chlorophylline properties) into a 

 green chlorophyll element, and a yellow element without the charac- 

 teristic optical marks of chlorophyll. 



On the spectrum of the yellow chromule of autumn leaves. 



In the examination of these leaves my object was to test whether 

 any chlorophylline chromule could be found which did not exhibit the 

 first four bands of the chlorophyll spectrum. Here certainly the pos- 

 sibility of an admixture with chlorophyll might be much sooner sus- 

 pected than in the case of anthoxanthin ; and accordingly perhaps 

 less value may be attached to the circumstance that in yellow autumn 

 leaves I have likewise failed to discover any purely yellow chromule 

 without chlorophyll bands in the red. These bands, however, are not 

 nearly so clearly seen as in the case of anthoxanthin and etiolin : a 

 result hardly to have been expected on the supposition of the chromule 

 of autumn leaves containing any possible admixture of chlorophyll. 



The author then gives the results of some experiments with the 

 alcoholic solutions made from faded Oleander leaves and old Rye straw, 

 from which he concludes that their chromutes possess the properties 

 ofj chlorophyll but only in a slight degree, only band I. having been as 

 yet seen, to show its origin from chlorophyll. 



III. — The yellow ingredient in the green leaf {chlorophyll). 



Since Fremy succeeded in separating an alcoholic solution of chlo- 

 rophyll into a yellow and blue component by means of muriatic acid 

 and ether, the view of the older botanists with regard to its green 

 colour depending on its containing two substances, has to some extent 

 been verified. It was, however, very soon demonstrated that acids 

 and alkalies have the power of changing the constitution of chlorophyll, 

 for it was proved that at least one of the two chromules obtained by 

 Fremy, viz., that taken up by the muriatic acid, is not an original 

 constituent of chlorophyll, but a result of its disintegration. A better 

 method of separating the component parts of chlorophyll has since been 

 made known, viz., that of using two non-miscible solvents, generally 



