URINE. 127 



some icteric urine and to the moistened paper add one drop of 

 HN0 3 . Colored rings around the drop correspond in color 

 and arrangement to those obtained in Gmelin's test. Cau- 

 tion : Impure filter-paper may give this test, so make a con- 

 trol test in using strange paper. 



(c) Haycraft's Test. Fill a test-tube half full of fresh 

 urine and sprinkle on the surface powdered sulphur. If the 

 sulphur sinks to the bottom the presence of bile salts is indi- 

 cated. This can only be used as a confirmatory test. 



BLOOD AND BLOOD PIGMENTS. 



Blood, as such, may be present in the urine (haBmaturia). 

 In these cases the urine is cloudy, brownish-red in color, and 

 contains serum albumin and serum globulin. Upon microscop- 

 ical examination blood corpuscles are found in the sediment. 



In ha3moglobinuria the form elements are absent and 

 the urine holds the oxyhsemoglobin in solution; metha3- 

 moglobin often accompanies it, and hsematin appears under 

 some conditions. In a number of diseases, but especially 

 after the use of sulphonal and similar therapeutic agents, 

 hsematoporphyrin has been observed in large quantities. 

 Reduced hemoglobin is never present. 



OXYH^EMOGLOBIN. 



(a) Notice the color of the urine. If fresh it has a reddish 

 tinge and is turbid. Try the benzidine reaction, (g) p. 73. 



(6) Examine it with the spectroscope. If the urine is not 

 fresh be on the lookout' for metha3moglobin. Warm a por- 

 tion of the urine with an excess of NaOH; filter and add a 

 few drops of (NH 4 ) 2 S. Oxy haemoglobin is changed to hasmo- 

 chromogen with its characteristic spectrum. 



(c) Heller's Test Make the urine strongly alkaline with 



