756 URINE. 



But the direct detection in a colored icteric urine is more difficult and gives very 

 misleading results; the bile-acid must therefore always be isolated from the urine. 

 This may be done by the following method of HOPPE-SEYLER, which is slightly 

 modified in non-essential points. 



HOPPE-SEYLER'S METHOD. Concentrate the urine and extract .the 

 residue with strong alcohol. The nitrate is freed from alcohol by evapo- 

 ration and then precipitated by basic lead acetate and ammonia. The 

 washed precipitate is treated with boiling alcohol, filtered hot, the filtrate 

 treated with a few drops of soda solution, and evaporated to dryness. 

 The dry residue is extracted with absolute alcohol, filtered, and an excess 

 of ether added. The amorphous or, after a longer time, crystalline, pre- 

 cipitate consisting of the alkali salts of the biliary acids is used in perform- 

 ing PETTENKOFER'S test. 



HAYCRAFT has suggested a reaction for clinical purposes which consists in 

 sprinkling flowers of sulphur upon the urine. In icteric urine the powder quicklv 

 sinks to the bottom, \vhile in normal urine is remains on the surface. The value 

 of this test is still questioned. 



Bile-pigments occur in the urine in different forms of icterus. A 

 urine containing bile-pigments is always abnormally colored yellow, 

 yellowish brown, deep brown, greenish yellow, greenish brown, or nearly 

 pure green. On shaking it froths and the bubbles are yellow or yellowish 

 green in color. As a rule icteric urine is somewhat cloudy, and the sedi- 

 ment is frequently, especially when it contains epithelium-cells, rather 

 strongly colored by the bile-pigments. In regard to the occurrence of 

 urobilin in icteric urine see p. 707. 



Detection of Bile-coloring Matters in Urine. Many tests have been 

 proposed for the detection of these substances. Ordinarily we obtain 

 the best results either with GMELIN'S or with HUPPERT'S test. 



GMELIN'S test may be applied directly to the urine; but it is better 

 to use ROSENBACH'S modification. Filter the urine through a very small 

 filter, which becomes deeply colored from the retained epithelium-cells 

 and bodies of that nature. After the liquid has entirely passed through 

 apply to the inside of the filter a drop of nitric acid which contains only 

 very little nitrous acid. A pale-yellow spot will be formed which is sur- 

 rounded by colored rings which appear yellowish red, violet, blue, and 

 green from within outward. This modification is very delicate, and it 

 is hardly possible to mistake indican and other coloring-matters for the 

 bile-pigments. Several other modifications of GMELIN'S direct test, e.g., 

 with concentrated sulphuric acid and nitrate, etc., -have been proposed, 

 but they are neither simpler nor more delicate than ROSENBACH'S modifica- 

 tion. 



HUPPERT'S Reaction. In a dark-colored urine or one rich in indican 

 good results are not always obtained with GMELIN'S test. In such cases, 

 as also in urines containing blood-coloring matters at the same time, 

 the urine is treated with lime-water, or first with some CaCl 2 solution, 

 and then with a solution of sodium or ammonium carbonate. The precipi- 

 tate which contains the bile-coloring matter is filtered, washed, dissolved 

 m alcohol which contains 5 cc. of concentrated hydrochloric acid in 100 



