174 Mr. C. A. Scliunck. T/ie Xantliopliyll [Air. 17, 



figs. 3 and 4). The first two bands are very intense, the third fainter,, 

 there is also a pronounced band a little less refrangible than the 

 solar line N, which is absent in the chrysophyll spectrum and which 

 appears to be less intense in the ethereal solution, though the other 

 bands are of the same intensity and occupy the same positions in the 

 two solvents. As with chrysophylls and the other xanthophylls the 

 ultra-violet rays are transmitted. Spectroscopic observation also- 

 shows that this substance constitutes nearly the whole of the pigment 

 present in the tomato, there being evidence of another in small- 

 quantities which can be formed from it by the action of acids, but 

 those that obscure the violet and ultra-violet are almost absent. Though 

 its ethereal solutions are fairly stable, a change soon takes place in the 

 alcoholic solutions, the colour changing from orange to yellow and 

 gradually becoming paler, at the same time the bands become fainter 

 and are replaced by three faint ones in the same positions as those of 

 B. xanthophyll. With HC1, H 2 S0 4 and HN0 3 a similar change 

 in the spectrum takes place, its alcoholic solutions gradually assuming 

 a pale yellow colour without any decided green tinge and finally 

 colourless. The spectrum produced by the action of acid upon 

 B. xanthophyll is not assumed, thus one cannot say whether the 

 yellow colouring matter which it undoubtedly gives rise to and the 

 gradual formation of which can be traced in the spectrum under 

 the influence of acid, is B. xanthophyll or not. A similar reaction 

 appears to take place with nascent H. Believing that this substance 

 has not been isolated before, or if it has, has been mistaken for 

 carotin, I venture to apply to it the name Lycopin. 



From the seeds of the annatto (Bixa Orellana) Bixin, to which the- 

 formula CosH^Cs has been given, can be obtained by dissolving the 

 annatto of commerce in boiling alcohol, which gives rise to a reddish- 

 brown crystalline mass on evaporation. If this be washed with a 

 little alcohol, dried, and dissolved in boiling glacial acetic acid, the 

 bixin crystallises on cooling and standing in the form of brownish-red 

 leaflets, which are soluble in alcohol, ether and carbon -bisulphide and 

 also in ammonia and sodium hydrate, but insoluble in water. It 

 resembles chrysophyll and lycopin in many respects, dissolving in 

 concentrated HoSCXi with a very intense blue colour, which soon 

 changes to purple and finally becomes reddish-brown. HNO 3 likewise 

 decomposes it and HC1 has no action even on boiling. The crystals 

 with a drop of HoS0 4 and HN0 3 turn a brilliant blue with the former 

 and the evanescent Prussian-blue coloration with the latter. Its 

 spectrum resembles chrysophyll save that the three bands which are of 

 the same intensity in each are less refrangible in position, being situated 

 between those of chrysophyll and lycopin, there is no band at N as- 

 in the latter, and the ultra-violet rays are transmitted. The alcoholic 

 solution is a rich orange-yellow which fades on the addition of HNOj 



