287 



test tube ; pour off the urine, and wash the pre- 

 cipitate with alcohol, then chloroform ; dissolve 

 in water and apply the biuret test. Test the 

 alcoholic extract for urobilin. 



Nucleo- Albumens. — Filter the urine carefully ; 

 boil to remove albumen ; then add gradually 

 excess of strong acetic acid. A turbidity indicates 

 nucleo-albumens. 



Blood (Haemoglobin, etc.) 



1. Examine Speciroscopically (Fig. 63). — If 

 the bands of methaemoglobin or oxyhaemoglobin 

 are seen, confirm by adding ammonium sulphide 

 when the bands of reduced haemoglobin are got. 



2. Heller s Test. — Make the urine strongly 

 alkaline with caustic soda ; boil ; the precipi- 

 tate in the presence of haemoglobin is bright 

 red ; confirm by dissolving the filtered precipitate 

 in acetic acid, a red solution is formed (spectro- 

 scopically this gives the characteristic bands of 

 haemachromogen). 



3. Guaiacum Test. — Equal parts of tincture 

 of guaiacum and oil of turpentine (which has been 

 exposed to the air) are taken ; add slowly to the 

 urine. A blue ring is formed at the junction 

 layer. 



Methaemoglobin 



The urine in blackwater fever when examined 

 early, most frequently contains blood pigment in 

 this form, later oxyhaemoglobin. This, according 

 to Hopee-Seyler, also holds good for every urine 

 with haemoglobin in solution. 



