PUS. BILE ACIDS. 799 



names indicate, seem to stand in close relation to the blood-coloring matters. 

 Urorubrohcematin, C68H94N 8 Fe 2 026, contains iron and shows in acid solution an 

 absorption-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 brownish-red 

 non-dichroic liquid with alkalies. Urofuscohcematin, CesHioeNgC^e, 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) hsematoporphyrin. 



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 XV). 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. They also give THORMAHLEN'S reaction namely a beautiful blue coloration 

 with sodium nitroprusside and then acetic acid. Urine containing melanin or 

 melanogen is colored black by a ferric-chloride solution (v. JAKSCH x ). 



In a case of melanotic sarcoma H. EPPINGER 2 has isolated from the urine 

 a crystalline melanogen of the composition C fl Hi 2 N 2 S04, and which was insoluble 

 in ether. It gave the ordinary melanogen reactions and, according to him is 

 probably an amidated ethereal sulphuric acid of methylpyrrolidinoxycarboxylic 

 acid, which is derived from tryptophane. 



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 DONNA'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 recognized 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 MAO 



^hormahlen, Virchow's Arch., 108; v. Jaksch, Zeitschr. f. physiol. Chem., 13. 

 2 Bioch. Zeitschr., 28. 



