280 URINE. [CH. XII. 



form solution and transfer it to a dry tube. The chloroform usually 

 separates as a clear fluid, which is of a faint pink colour if urobilin 

 is present. A characteristic absorption band, with centre about 

 X 500 can be seen. 



326. Schlesinger's test for urobilin. To 10 cc. of urine 

 add 3 drops of a 5 per cent, alcoholic solution of iodine ( to convert 

 urobilinogen to urobilin). Into another test : tube place I gram, of zinc 

 acetate and 10 cc. of absolute alcohol. Mix the two solutions and 

 repeatedly decant until all the zinc acetate has dissolved. Filter. 

 Examine the filtrate in a test-tube, 16 mm. wide, in daylight falling 

 from behind the observer. A green fluorescence is seen if urobilin 

 or urobilinogen are present. 



NOTE. The above method is a modification introduced by Marcussen 

 and Hansen (Journ. Biol. Chem., xxxvi., p. 381). They state that ammoniacal 

 urines should be acidified with acetic acid. They find that in patients suffering 

 from liver complaints they can detect the fluorescence when the urine has been 

 diluted 40 to 80 times, and are of the opinion that unless it can be detected in a 

 dilution of r in 20 a pathological urobilinuria has not been definitely established. 



D. The Inorganic Constituents. 



Rations. 



Sodium and potassium are found to the extent of 

 3-2 gram. K 2 O and 5-23 gram. Na 2 O per diem. The ratio 

 K 2 O : Na 2 O generally equals i : 1-54. 



During starvation this can rise as high as 3:1, owing 

 to the excretion of the potassium of the tissues, sodium 

 being found in a much smaller amount than potassium. 

 The same is found in all wasting diseases. 



Calcium and Magnesium are mainly excreted by the 

 bowel. The amounts in urine are 0-33 to 0-6 gram. CaO 

 and 0-16 to 0-24 gram, of MgO. 



The amounts of these alkaline earths in the urine are 

 increased by the administration of organic acids, or in 

 conditions such as diabetes in which the formation of such 

 acids is increased. 



Iron also is mainly excreted by the bowel. It is found 

 in human urine only in organic combination, and then 

 only to the extent of 0-5 to 10 milligrams per diem. 



