170 Mr. C. A. Schunck. The Xanthophyll [Apr. IT, 



Y. which under the action of the acid give rise to a blue pigment which 

 is reconverted into them by the addition of alkali and vice versd. The 

 same reaction takes place with H 2 S0 4 and HN0 3 but the colour effects 

 are not so brilliant. In the dry state both chrysophyll and L. 

 xanthophyll as well as the B. and Y. turn a Prussian-blue colour with 

 a drop of concentrated HN0 3 which is evanescent, an indigo-blue with 

 concentrated H 2 S0 4 which is more lasting, and the two latter assume a 

 green colour with concentrated HC1, there being no alteration in colour 

 the two former in this case. 



Leaves. 



From the concentrated alcoholic extracts of healthy green leaves, as 

 is well known, minute sparkling red crystals having a me tallic^ lustre 

 form in the course of a day or so, and in cases where deposits form from- 

 the hot extracts on cooling, the crystals will also be found embedded in 

 it. This substance which appears to be universally present in all green 

 leaves but varying in amount, is the Chrysophyll of Hartsen and 

 Schunck*, and according to Arnaudf is identical with Carotin, the 

 crystalline substance obtained from the carrot root and which name he 

 applies to it. These minute crystals from the green leaf extracts can 

 be freed from chlorophyll and the other colouring matters present by 

 washing with cold alcohol in which they are almost insoluble and 

 recrystallising from ether in which they are very soluble, and from 

 which this substance crystallises in the form of beautiful red metallic 

 leaflets on slow evaporation. Chrysophyll is also soluble in boiling 

 alcohol and glacial acetic acid, readily soluble in carbon-bisulphide, but 

 insoluble in alkalies. No very definite chemical reactions of this 

 substance so far are known, it is not a stable body and in contact with 

 the air soon decomposes, it can, however, be preserved in an atmosphere 

 of hydrogen without change. HC1 has no effect upon the crystals,, 

 they dissolve, however, in concentrated HoS0 4 producing a deep Prussian- 

 blue solution which soon changes to purple and then brown, and HN0 3 

 decomposes them at once. The colour reactions the crystals assume as 

 mentioned above with a drop of concentrated HN0 3 and H 2 S0 4 appear 

 to be a general reaction of this group of colouring matters. According 

 to TschirchJ who applies to it the name Xanthe-Carotin, this substance 

 forms with iodine a green derivative. 



The absorption spectrum of three pronounced bands situated 

 between F. and H (Plate 7. fig. 1) appears to be the most characteristic 

 and distinguishable property of chrysophyll which on the addition of a 

 small quantity of HN0 3 to the alcoholic solution undergoes similar 

 changes to that which L. xanthophyll passes through the bands fading. 



* * Eoy. Soc. Proc.,' rol. 44, p. 449. 



t ' Compt. Bend.,' vol. 102, p. 1119, and vol. 104, p. 1293. 



J ' Berichte der Deutschen Botanischen O-esellschaft,' vol. 14, Tarl IT, p. 84.. 



