Colouring-matters of the so-called Bile of Invertebrates, 8cc. 399 



the latter case the addition of nitric acid would cause the disappear- 

 ance of the bands near D, while in the case of indigo-blue no effect 

 would be produced. I have tried the effect of the above treatment on 

 solutions of bile-pigment and on bilicyanin, and find that they behave 

 quite differently from indican. When febrile urobilin, or urohasmatin, 

 or uroerythrin, or other pigment is present, this test is still appli- 

 cable, and will probably be found of great use in clinical work. (See 

 sp. 18.) 



TJroerijthrin. — A hot alcohol extract of uroerythrin from pink urates 

 always gives a double absorption band from about three-fourths the 

 distance between D and E to beyond F, and therefore differs most 

 decidedly in spectrum from that figured by Dr. Thudichum ;* instead 

 of showing the three well-defined bands figured by him, it always 

 gives a hazy double band or shading in the position described. The 

 uroerythrin which I examined always answered to the description, as 

 regards chemical character, given in books on physiological che- 

 mistry, which I need not repeat. I have figured this spectrum in 

 sp. 19, for comparison. I cannot trace any connexion between uro- 

 erythrin and indican or urobilin, but it often accompanies uro- 

 haematin ; and it will be found probably derived from a radical 

 belonging to the aromatic group of carbon compounds. 



A "peculiar Med Colouring -matter in Pale, Urine. — When urine 

 becomes red on the addition of a mineral acid one is apt to conclude 

 that this is due to the formation of indigo-red or urrhoclin, or 

 possibly that oxidation of the chromogen of urobilin has taken place, 

 or that a bile pigment may be present, but the specimens of urine 

 which I am about to refer to, contained a pigment which was not One 

 nor the other, as its various spectra showed. 



The specimen of urine was sent to me by Dr. Carter of Birminghamf 

 who informed me that it came from " an anaemic sickly fellow " who 

 was taking copaiba and sandal-wood oil for chronic blenorrhcea. I may 

 here state that the urine of other patients taking these drugs failed to 

 show any sign of the presence of the pigment. The first specimen of 

 urine only amounted to about an ounce, and owing to an accident half 

 of it was lost. It had a pale straw colour, was faintly acid, and gave 

 the band of normal urobilin. 



When treated with nitric acid in the cold it changed to a splendid 

 ruby-red colour and gave a very feeble band at D, and a very dark 

 one between D and E and touching E, the latter from \558 — 534 ; the 

 feeble shading perhaps from \612 — 589 ? ; but on boiling with nitric 

 acid this red colour was destroyed, it became yellow, and the bands 

 were no longer seen. On adding hydrochloric acid the same feeble 

 band appeared at D, and in a deep layer the whole spectrum up to 



* " Journ. Chera. Soa," 1875 (2), vol. 13, p. 389. 

 f On January 24, 1882. 



