PUS. BILE ACIDS. 755 



tion-band in front of D and a broader one back of D. In alkaline solution it 

 shows four bands behind D, at E, beyond F, and behind G. It is not soluble 

 either in water, alcohol, ether, or chloroform. It gives a beautiful bro\vnish-red 

 non-dichroic liquid with alkalies. Urofuscohcematin, C 68 H 106 N 8 26 , which is free 

 from iron, shows no characteristic spectrum; it dissolves in alkalies, producing 

 a brown color. It remains to be proven whether these two pigments are related 

 to (impure) haematoporphyrin. 



Melanin. In the presence of melanotic cancers dark pigments are some- 

 times eliminated with the urine. K. MORNER has isolated two pigments from 

 such a urine, of which one was soluble in warm 50-75 per cent acetic acid, while 

 the other, on the contrary, was insoluble. The one seemed to be phymatorhusin 

 (see Chapter XVI). Usually the urine does not contain any melanin, but a 

 chromogen of melanin, a melanogen. In such cases the urine gives EISLET'S 

 reaction, becoming dark-colored with oxidizing agents, such as concentrated 

 nitric acid, potassium bichromate, and sulphuric acid, as well as with free sulphuric 

 acid. Urine containing melanin or melanogen is colored black by a ferric-chloride 

 solution (v. JAKSCH *). 



Pus occurs in the urine in various inflammatory affections, especially 

 in catarrh of the bladder and in inflammation of the pelvis of the kidneys 

 or of the urethra. 



Pus is best detected by means of the miscroscope. The pus-cells are 

 rather easily destroyed in alkaline urines. In detecting pus we make 

 use of DONNE'S pus test, which is performed in the following way: Pour 

 off the urine from the sediment as carefully as possible, place a small 

 piece of caustic alkali on the sediment, and stir. If the pus-cells have 

 not been previously changed, the sediment is converted by this means 

 into a slimy tough mass. 



The pus-corpuscles swell up in alkaline urines, and dissolve, or at least 

 are so changed that they cannot be recognizeol under the microscope. 

 The urine in these cases is more or less slimy or fibrous, and the proteid 

 can be precipitated in large flakes by acetic acid, so that it might possibly 

 be mistaken for mucin. The closer investigation of the precipitate 

 produced by acetic acid, and especially the appearance or non-appearance 

 of a reducing substance after boiling it with a mineral acid, demonstrates 

 the nature of the precipitated substance. Urine containing pus always 

 contains proteid. 



Bile-acids. The reports in regard to the occurrence of bile-acids in the 

 urine under physiological conditions do not agree. According to DRAGEN- 

 DORFF and HONE traces of bile-acids occur in the urine; according to MAC- 

 KAY and v. UDRANSZKY and K. MORNER 2 they do not. Pathologically 

 they are present in the urine in hepatogenic icterus, although not invar- 

 iably. 



Detection of Bile-acids in the Urine. PETTENKOFER'S test gives the most 

 decisive reaction ; but as it gives similar color reactions with other bodies, it must 

 be supplemented by the spectroscopic investigation. The direct test for bile- 

 acids is easily performed after the addition of traces of bile to a normal urine. 



1 K. Morner, Zeitschr. f. physiol. Chem., 11; v. Jaksch, ibid., 13. 



2 Cited from Huppert-Neubauer, Hani-Analyse, 10. Aufl. 229. 



