394 



Dr. C. A. MacMunn. 



form, bat tlie chloroform failed to take much, colouring-matter up ; a 

 deposit formed, being precipitated by the chloroform, which, when 

 dissolved in alcohol, formed a fine blue solution, giving a band before 

 D and one at F, the first from X616— 590*5, the second \507— 486* 

 By further addition of nitric acid to this solution it could be made to 

 show a band after D ; it was then shaken with chloroform, and the 

 latter separated off was a purple-red by gaslight, and gave 



If these measurements are compared with those of the bands of a 

 similar solution of ox or sheep bile colouring-matter a wide difference 

 is apparent. Hence the pigments of sheep or ox bile and that pro- 

 duced from bilirubin by oxidising agents are not the same. 



Another spectrum can be got by acting on bilirubin in alkaline 

 aqueous solution with potassium permanganate ; by cautious addition 

 of this reagent a band appears in the space between D and B, and 

 touching the latter line ; but on adding more permanganate it dis- 

 appears and a green solution is formed, which is merely due to the 

 action of the caustic soda, used in dissolving the bilirubin, on the 

 permanganate. 



In former papers I have described four pigments, namely, febrile 

 urobilin, normal urobilin, urohcematin, and urolubein. I have here to 

 refer to the spectroscopic detection of indican in urine, to uroerythrin, 

 and to a peculiar colouring-matter met with in pale urine. I am more 

 convinced than ever that only by the use of the spectroscope can 

 these pigments be distinguished from each other ; and the condition 

 of the first three furnishes one with an exact test of the amount of the 

 metabolism of heemoglobin, and of the oxidation or reduction going 

 on in the organism. I have first to refer to some matters bearing on 

 former results. 



The Spectrum of Febrile Urobilin. — I have made measurements of 

 the bands of solutions of this pigment, as those in my first paperf 

 were not made with the help of the more exact method of measuring 

 now at my disposal. J The pigment was obtained by means of the 

 method described in former papers. 



* A shading was perceptible after D from X589 — 548? 

 f " Proc. Roy Soc," 1880, vol. 31, p. 26. 



X All the wave-lengths in this paper are calculated by means of an interpolation 

 curve adapted to the scale of a one-prism chemical spectroscope, as the microspec- 

 troscope cannot be sufficiently relied upon for accurate work. 



] st Band 

 2nd „ 

 3rd „ 



A.620— 592 or 590 '5 

 X583— 548 

 X509— 486 



III. On some Unusual Urine Pigments, &c. 



