291 



2. Huppevfs Test. — Precipitate the urine 

 with BaClj. Filter ; wash the residue off the 

 filter (perforated) with acidulated H^SO^ 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 i, alcohol 10). A green ring forms at the 

 junction zone. 



Bilirubin and Haematoidin (in Urinary 

 Sediment) 



1. Bilirubin crystals form yellowish-brown 

 rhomboidal plates or needles. 



Easily soluble in CHCl,. Gives Gmelin's 

 reaction, green, under the microscope. 



2. Haematoidin, dark-red in colour or 

 greenish if impure, with nitric acid they give a 

 transient blue. 



According to Hoppe-Seyler, however, they 

 are identical. 



Haematoporphyrin 



Occurs in urine as alkaline haematoporphyrin 

 (Fig. 64). In urate sediments a similar form occurs. 

 It is soluble in chloroform, giving bands similar 

 .to those of oxyhaemoglobin, but acid converts 

 this into acid haematoporphyrin bands. Solu- 

 tions have a brilliant red fluorescence. It is 

 found in the urine in toxic conditions, such as 

 chronic sulphonal poisoning. It is precipitated 

 by lead acetate, while oxyhaemoglobin is not. 



Sugar 



Before testing for sugar, boil to remove all 

 proteids. 



