708 URINE. 



is precipitated from the urine by saturating with ammonium sulphate. 

 According to SAILLET it may be extracted by acetic ether from urine 

 acidified with acetic acid. It also dissolves in chloroform, ethyl-ether 

 and amyl-alcohol. It shows no absorption-bands and is readily converted 

 into urobilin by the influence of sunlight and oxygen, and, according to 

 NEUBAUER and BAUER, 1 gives the EHRLICH reaction with dimethylamido- 

 benzaldehyde and hydrochloric acid (see below). 



In preparing urobilin from normal urine, precipitate the urine with 

 basic lead acetate (JAFFE), wash the precipitate with water, dry at the 

 ordinary temperature, then boil it with alcohol, and decompose it when 

 cold with alcohol containing sulphuric acid. The filteied alcoholic 

 solution is diluted with water, saturated with ammonia, and then treated 

 with zinc-chloride solution. This new precipitate is washed free from 

 chlorine with water, boiled with alcohol, dried, dissolved in ammonia, 

 and this solution precipitated with sugar of lead. This precipitate, 

 which. is washed with water and boiled with alcohol, is decomposed by 

 alcohol containing sulphuric acid, the filtered alcoholic solution is mixed 

 with ^ vol. chloroform, diluted with water, and shaken repeatedly, but 

 not too energetically. The urobilin is taken up by the chloroform. This 

 last is washed once or twice with a little water and then distilled, leaving 

 the urobilin. The pigment may be precipitated directly from the urine 

 rich in urobilin by ammonia and zinc chloride, and the precipitate treated 

 as above described (JAFFE). 



The method suggested by MEHU (precipitation with ammonium sul- 

 phate) has been modified by GARROD and HOPKINS in that they first 

 remove the uric acid by saturating with ammonium chloride and then 

 saturating the filtrate with ammonium sulphate. In regard to small 

 details, and to a second method suggested by these experimenters, we 

 refer to the original work. 2 



SAILLET extracts the urobilinogen from the urine by shaking with 

 acetic ether, using a kerosene-oil light. In regard to this and other 

 methods we must refer to other hand-books. 



The color of the acid or alkaline solution, the beautiful fluorescence 

 of the ammoniacal solution treated with zinc chloride, and the absorp- 

 tion-bands of the spectrum, all serve as means of detecting urobilin. 

 In fever-urines the urobilin may be detected, directly, or after the addi- 

 tion of ammonia and zinc chloride, by its spectrum. It may also some- 

 times be detected in normal urine, either directly or after the urine has 

 stood exposed to the air until the chromogen has been converted into 

 urobilin. If it cannot be detected by means of the spectroscope, then 

 the urine may be treated with a mineral acid and shaken with ether or, 

 still better, with amyl alcohol. The amyl-alcohol solution is, either 

 directly or after addition of a strongly ammoniacal alcoholic solution 

 of zinc chloride, tested spectroscopically. According to SCHLESINGER 3 

 it can be readily detected if the urine is precipitated by an equal volume 



1 Neubauer, cited from Centralbl. f. PhysioL, 19, 145; Bauer, cited from Biochem. 

 Centralbl., 4, 390. 



2 Journ. of PhysioL, 20. 

 3 Deutsch. med. Wochenschr., 1903. 



