THE URINE 469 



Acetone gives a peculiar fruity odour to the urine. It is best 

 detected by Rothera's test. Ten c.c. of urine are saturated with, 

 ammonium sulphate by adding the solid salt, and a few drops of a 

 solution of sodium nitro-prusside and 2 to 3 c.c. of strong ammonia 

 added. On allowing to stand, a colour appears like that of perman- 

 ganate of potash. Urine containing acetone will also yield the charac- 

 teristic odour of iodoform when an alcoholic solution of iodine and a. 

 little strong ammonia are added to it. 



Levulose. Levulosuria by itself is a rare condition, but le'vulose 

 occurs in the urine with dextrose in cases of " mixed mellitu ia." 

 The polarimeter and the resorcin test are used for its detection. 



Lactose. " Lactosuria " occurs sometimes in mothers who are 

 .suckling their children. The sugar may occur in quite appreciable 

 amount in the urine. The chief points which aid in its detection are these : 

 it reduces Fehling's solution ; it does not ferment with yeast ; it yields 

 characteristic small rosettes with the phenyl-hydrazine test (see p. 65). 



Pentose. " Pentosuria " is a rare condition. It may occur tem- 

 porarily as the result of large ingestion of fruit; such as cherries, 

 grapes, and plums. Occasionally, a pentose occurs in conjunction 

 with dextrose in cases of glycosuria. There is a rare anomaly of 

 metabolism in which pentose occurs regularly in the urine. Such a, 

 pentosuria is accompanied by no morbid symptoms, is probably 

 harmless, and needs no treatment. The pentose in question is usually 

 arabinose. The low melting-point of the osazone (160 C.), the non- 

 fermentation with yeast, and Bial's orcin test, serve to indicate the 

 presence of a pentose in the urine. 



Bile in the Urine. In the condition known as " jaundice," bile 

 appears in the urine. As the result of obstruction of the bile -passages T 

 bile enters the blood, and so reaches the urine. The bile pigments 

 generally confer a greenish or brownish colour on the urine. They 

 may be detected by the play of colours formed when fuming nitric 

 acid is added (Gmelin's test). The presence of bile salts in the urine 

 may be best shown by Hay's sulphur test. If " flowers " of sulphur 

 are sprinkled on the surface of urine containing bile, the sulphur sinks 

 readily. 



Alkaptonuria is due to an inborn anomaly affecting protein meta- 

 bolism. It is of interest as throwing light on the halfway stages of 

 protein decomposition, for it seems probable that the breaking down 

 of the tyrosin group is not carried so far as usual, rather than that 

 an abnormal body is formed. In the urine, homogentisic acid, (di- 

 hydroxyphenylacetic acid) is secreted. 



OH 



ICHo.COOH 

 OH 



