706 URINE. 



N 9.22 (MALY), while urinary urobilin, on the contrary, contains C 63.46, 

 H 7.67, N 4.09 per cent. The urobilin from feces, stercobilin, has the same 

 composition as urinary urobiiin with 4.17 per cent nitrogen. 



Urinary urobilin may not be identical with hydrobilirubin, but this 

 does not exclude the possibility that urobilin, according to the generally 

 admitted view, is derived from bilirubin (although not by simple reduction 

 and taking up of water) in the intestine. Several physiological as well as 

 c.inical observations 1 point to the truth of this theory, among which we 

 must mention the regular appearance in the intestinal tract of stercobilin, 

 undoubtedly derived from the bile-pigments and having the same composi- 

 tion as urinary urobilin, the absence of urobilin in the urine of new-born 

 infants as well as on the complete exclusion of bile from the intestine, and 

 also the increased elimination of urobilin with strong intestinal putrefac- 

 tion. On the other hand there are investigators who, basing their opinion 

 on clinical observations, deny the intestinal origin of urobilin and claim 

 that the urobilin is derived from a transformation of the bilirubin else- 

 where than in the intestine, by an oxidation of the bile-pigment or by a 

 ti ansf ormation of the blood-pigments. 2 The possibility of a different 

 mode of formation of urinary urobilin in disease is not to be denied; but 

 there is no doubt that this pigment is formed from the bile-pigments in 

 the intestine under physiological conditions. 



Urobilin does not occur in the urine of all animals, and according to 

 FROMHOLDT it is absent in the urine as well as in the feces of rabbits. 

 BIFFI 3 finds abundance of urobilin or urobilinogen in the blood of human 

 cadavers, while it is normally absent in the blood during life. In cases 

 with inflammation of the lungs it occurs according to BIFFI in the blood 

 during life. 



The quantity of urobilin in the urine under physiological conditions 

 varies widely. SAILLET found 30-130 milligrams and G. HOPPE-SEYLER 

 80-140 milligrams in one day's urine. 



There are numerous observations on the elimination of urobilin in 

 disease, especially by JAFFE, DISQUE, GERHARDT, G. HoppE-SEYLER, 4 



1 See Fr. Miiller, Schles. Gesellsch. f. vaterl. Kultur, 1892; D. Gerhardt, " Ueber 

 Hydrobilirubin und seine Bezieh. zurn Ikterus " (Inaug.-Diss., Berlin, 1889); Beck, 

 Wien. klin, Wochenschr., 1895; Harley, Brit. Med. Journ., 1896; Fischler, Zeitschr. 

 f physiol. Chem., 48. 



2 In regard to the various theories as to the formation of urobilin, see Harley, 

 Brit. Med. Journ., 1896; A. Katz., Wien. med. Wochenschr., 1891, Nos. 28-32; Grimm, 

 Virchow's Arch., 132; Zoja, Conferenze cliniche italiane, Ser. la, 1; Hildebrandt, 

 Zeitschr. f. klin. Med., 59; Biffi, Boll. d. scienc. med. di Bologna (8), anno 78, 7. 



3 Fromholdt, Zeitschr. f. physiol. Chem., 59; Biffi, Folia hsematol, 4, and 1. c. 

 Boll., 78. 



4 In regard to the literature on this subject we refer the reader to D. Gerhardt, 

 " Ueber Hydrobilirubin und seine Beziehungen zum Ikterus " (Berlin, 1889), and 

 also G. Hoppe-Seyler, Virchow's Arch., 124. 



