Colouring-matters of the so-called Bile of Invertebrates, fyc. 383 



depth of alcoholic solution a band became detached at F, which on 

 adding caustic soda was slightly narrowed, and read from X509 — 490. 

 The ether solution gave similar bands, but in addition it appeared to 

 contain a lutein pigment, as two bands could be seen in the blue and 

 violet, the first from X498— 480, the second from X466— 450. Of 

 course in this and other cases the possibility of the presence of a 

 xanthophyll must not be lost sight of, but in the present stage of the 

 inquiry I believe these bands are due to lutein. A chloroform 

 solution showed the chlorophyll bands like the other solutions, and 

 also two others, of which one extended from X509 — 488, the other 

 X474 — 456 (?) Another brown specimen of Uraster contained green 

 coeca, and the alcoholic extract of these gave the chlorophyll bands 

 (see 14th sp.), four in number, of which the following are the 

 measurements : — 



1st Band A674— 643 Centre 656 



2nd „ X614— 596 „ 604 



3rd „ X545— 534 „ 540 '5 



4th „ X516— 494 „ 505 



This solution became greenish-blue with nitric acid and the 

 spectrum of sp. 15 now was seen; the following are the measure- 

 ments : — 



1st Band \661— 643 



2nd „ X608— 590-5 



3rd „ X580— 561 



4th „ X539— 518 



5th „ X505-484 



Caustic soda changed the spectrum of an alcoholic solution in a 

 remarkable manner, for while the band in red remained as before, 

 that before D became replaced by two narrow bands. They gave 

 the following readings : — 



1st Band X668— 646 



2nd „ X630-616 



3rd „ X552— 536 



4th „ X516— 494 



Only one of the feeble bands referred to above is accounted for, as 

 the other faded away. The solution assumed a yellow colour at the 

 same time. 



An alcoholic solution of orange-coloured cceca gave a band in red 

 from X670 — 656, and a similar solution of green-brown coeca gave 

 the same band, the latter also formed an orange solution with 

 chloroform which gave two bands, one from X507 — 486, the other 

 from X474 — 456. In both cases a considerable portion of the blue 



