UROBILIN. 745 



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 or 

 urobilinogen in disease, especially by JAFF, DISQU, GERHARDT, G. 

 HOPPE-SEYLER, 1 and others. The quantity is increased in hemorrhage 

 and in disease where the blood-corpuscles are destroyed, as is the case 

 after the action of certain blood-poisons, such as antifebrin and anti- 

 pyrine. It is also increased in fevers, cardiac diseases, lead colic, atrophic 

 cirrhosis of the liver, and is especially abundant in so-called urobilin 

 icterus. 



The properties of urobilin may vary, depending upon the method 

 of preparation and the character of the urine used; therefore only the 

 most important properties will be given. Urobilin is amorphous, brown, 

 reddish brown, red, or reddish yellow, depending upon the method 

 of preparation. It dissolves readily in alcohol, amyl alcohol, and 

 chloroform, but less readily in ether or acetic ether. It is less soluble 

 in water, but the solubility is augmented by 'the presence of neutral 

 salts. It may be completely precipitated from the urine by saturating 

 with ammonium sulphate, especially after the addition of sulphuric acid 

 (MEHU 2 ). It is soluble in alkalies, and is precipitated from the alkaline 

 solution by the addition of acid. It is partly dissolved by chloroform 

 from an acid (watery-alcoholic) solution; alkali solutions remove the 

 urobilin from the chloroform. The neutral or faintly alkaline solutions 

 are precipitated by certain metallic salts (zinc and lead), but not by others, 

 such as mercuric sulphate. Urobilin is precipitated from the urine by 

 phosphotungstic acid. It does not give GMELIN'S test for bile-pigments. 

 It gives, on the contrary, a reaction which may be mistaken for the biuret 

 test, by the action of copper sulphate and alkali. 3 



Neutral alcoholic urobilin solutions are, in strong concentration, 

 brownish yellow, in great dilution yellow or rose-colored. They have a 

 strong green fluorescence. The acid alcoholic solutions are brown, 

 reddish yellow, or rose-red, according to concentration. They are not 

 fluorescent, but show a faint absorption-band, X, between b and F, which 

 borders on F. The absorption maximum lies according to LEWIN and 

 STENGER 4 at 7 = 494-497. The alkaline solutions are brownish yellow, 



1 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. 



2 Journ. de Pharm. et Chim., 1878, cited from Maly's Jahresber., 8. 



3 See Salkowski, Berlin, klin. Wochenschr., 1897, and Stokvis, Zeitschr. f. Biologic, 

 34. 



4 Pfliiger's Arch., 144. 



