URINE 405 



CH 



/\ 

 HC C C.OH 



2 | || || - + 20 



HC C CH 



\/\/ 

 CHNH 



Indoxyl, CsHvNO. 



CH CH 



/\ /V 



HC C C:0 0:C C CH 



| || | I II I + 2H * 



HC C C C C CH 



%/\/ \/\/ 



CH NH NH CH 



Indigo-blue, CuHioNzOz.. 



a. Obennayer's Test.-Nearly fill a test-tube with a mixture composed of 

 equal volumes of Obennayer's reagent' and the urine under examma on 

 Add 2-3 c.c. of chloroform, place the thumb over the end of the test-tube and 

 shake thoroughly. How does this compare with Jaffe's test ? 



. Tolles' Reaction.'-To 10 c.c. of urine add i c.c. of a 5 per cent afcohohc 

 thymo solution and shake. Add about to c.c. of fuming HC1 contammg 5 

 grams of ferric chloride per liter. Shake again carefully and let stand i 

 Lutes. Add about 4 c.c. of chloroform and extract the p.gment by repeated 

 gentle shaking. The chloroform becomes intensely violet. 0.0032 rag. o: 

 S^a be detected in 10 c.c. of urine. It is much the most dehcate test for 



mdican ' CO.NH.CH 2 .COOH. 



t 



HIPPURIC ACID, 



This acid occurs normally in the urine of both the carnivora and 

 herbivora but is much more abundant in the urine of the latter, 

 formed by a synthesis of benzoic acid and glycocoll which takes place 

 in the kidneys and elsewhere. 3 The glycocoll comes from decomposi- 

 tion of protein. The benzoic acid thus utilized may come from (i) pre- 

 formed benzoic acid of fruits and vegetables; (2) other aromatic com- 

 pounds of fruits and vegetables; (3) aromatic ammo-acids (tyrosme 

 and phenylalanine) from the alimentary tract. The average excretion 

 of hippuric acid by an adult man for 24 hours under normal conditions 

 is about 0.7 gram. Hippuric acid crystallizes in needles or rhombic 

 prisms (see Fig. 130, p. 406) the particular form depending upo 



Obermayer's reagent is prepared by adding 2-4 grams of ferric chloride to a liter of con- 

 centrated HC1 (sp. gr. 1.19). 



2 Zeil. pkysiol. Chem., 94, 79> I9 I 5- 



Kingsbury and Bell: Jour. Biol. Chem., 21, 297, 



