UROERYTHRIN. 709 



of a 10 per cent solution of zinc acetate in absolute alcohol. Disturb- 

 ing bodies are here precipitated and the filtrate gives the fluorescence 

 directly, and also the spectrum. GRIMBERT * has given another com- 

 paratively simple method. 



The detection of urobilin in feces can be accomplished in various 

 ways and very simply by the aid of alcoholic extracts as suggested by 



SALKOWSKI. 2 



In the quantitative estimation of urobilin we proceed as follows, 

 according to G. HOPPE-SEYLER: 3 100 cc. of the urine are acidified with 

 sulphuric acid and saturated with ammonium sulphate. The precipitate 

 is collected on a filter after some time, washed with a saturated solu- 

 tion of ammonium sulphate, and repeatedly extracted with equal parts 

 of alcohol and chloroform after pressing. The filtered solution is treated 

 with water in a separately funnel until the chloroform separates well 

 and becomes clear. The chloroform solution is evaporated on the water- 

 bath in a weighed beaker, the residue dried at 100 C., and then extracted 

 with ether. The ethereal extract is filtered, the residue on the filter cjis- 

 solved in alcohol, and transferred to the beaker and evaporated, then 

 dried and weighed. According to this method G. HOPPE-SEYLER found 

 0.08-0.14 gram of urobilin in one day's urine of a healthy person, or an 

 average of 0.123 gram. 



Urobilin may also be determined spectrophotometrically according to FR. 

 MULLER or SAILLET. 4 SAILLET found that the limit for the perceptibility of 

 the absorption-bands of an acid-urobilin solution lies in a concentration of 1 

 milligram of urobilin in 22 cc. of solution when the thickness of the layer of fluid 

 is 15 mm. In a quantitative estimation the urobilin solution is diluted to this 

 limit and then the quantity of urobilin calculated from the extent of dilution. 

 The freshly voided urine, shielded from light, is acidified with acetic acid, com- 

 pletely extracted in kerosene-oil light with acetic ether, and the dissolved uro- 

 bilinogen oxidized to urobilin with nitric acid. On the addition of ammonia 

 and shaking with water the urobilin passes into the watery solution. This is 

 acidified with hydrochloric acid and diluted until the above limit is reached. 



Uroerythrin is the pigment which often gives the beautiful red color to 

 the urinary sediments (sedimentum lateritium). It also frequently occurs, 

 although only in very small quantities, dissolved in normal urines. The 

 quantity is increased after great muscular activity, after profuse perspira- 

 tion, immoderate eating, or partaking of alcoholic drinks, as well as after 

 digestive disturbances, fevers, circulatory disturbances of the liver, and in 

 many other pathological conditions. 



Uroerythrin, which has been especially studied by ZOJA, RIVA, and 

 GARROD, 5 has a pink color, is amorphous, and is very quickly destroyed 

 by light, especially when in solution. The best solvent is amyl alcohol; 



' See Chem. Centralbl., 1904, 1, 1623. 



2 Arbeit, aus. d. pathol. Inst. Berlin. Festschr., 1906. 



3 Virchow's Arch., 124. 



4 Fr Muller, see Huppert-Neubauer, 861; Saillet, 1. c. 



5 Zoja, Arch. ital. di clinica med., 1893, and Centralbl. f. d. med. Wissensch., 1892; 

 Riva. Gaz med di Torino, Anno 43, cited from Mary's Jahresber., 24; Garrod, Journ. 

 of Physiol., 1" and 21. 



