2 IP 
Characteristics :— 
1. In acid urine a band near F occurs, between 
88 and ioi. 
2. In alkaline urine a band between 8i and 95. 
3. Make the urine strongly alkaline with 
ammonia, filter, add ZnCl 2 solution, but not sufficient 
to form a permanent precipitate. 
A green fluorescence occurs, and the much 
clearer band nearer £ b ’ than the acid band. 
Detection :— 
1. If oxyhaemoglobin is present. Precipitate 
the urobilin with basic lead acetate, then acidify the 
precipitate, when the urobilin goes into solution. 
2. If methaemoglobin is present. Neutralize 
the urine with carbonate of soda ; precipitate the 
methaemoglobin with neutral lead acetate. Filter ; 
test the filtrate for urobilin. 
Bile Pigments 
Where urobilin is present, as in blackwater, the 
colour of the foam on shaking the urine, the staining 
of the filter paper, etc., cannot be regarded as satis¬ 
factory tests. 
Detection :— 
1. Gmelin-Rosenbach Test. — Filter the urine 
through filter paper (Swedish). Dry ; apply a drop 
of nitric acid (fuming) to this, a play of colours is got. 
2. Hubert's Test. —Precipitate the urine with 
BaCl 2 . Filter ; wash the residue off the filter (per¬ 
forated) with acidulated (H 2 S 0 4 ) alcohol. Boil. A 
bright green colour indicates bilirubin. 
3. Smith's Test. —To ten c.c. of the urine add 
two c.c. of dilute tincture of iodine (tincture of iodine 
1, alcohol 10). A green ring forms at the junction 
zone. 
