GLYCOSURIA. 173 



oxide (Cu 2 O) occurs, which, if well marked and abundant, 

 indicates either sugar or glycuronic acid. The latter is 

 not very common, but should be remembered. 



NOTE. In this test if performed with H 2 0, the hydrated copper 

 oxide produced by the alkali on CuSo is insoluble, and heated to 100 C. 

 falls as a black pp. Ordinary urine differs from H^O in keeping the 

 hydrated oxide in solution, and yields a slight reaction due to uric acid > 

 hippuric acid, creatinin, alcapton, albumin, nucleo albumin, bile pigments. 

 These may veil the reaction due to the minute trace of sugar normally 

 present. Fehling's solution and Barfoed's reagent give the same reaction. 



(b) Bismuth Salt. Nylander's test. To 10 volumes urine add 



1 volume of the following solution : 2 g basic nitrate of 

 bismuth, 4 g Rochelle salt, 100 CC of a solution containing 

 10-33 g NaOH. Boil 5 to 10 minutes. A black pp forms 

 (said to show as little as '04 lxc - sugar). Albumin gives 

 it also, 6 p - c - a red brown pp, and 1-2 p - c - a black pp. 



Pure peptone does not give the reaction (Le Nobel). 



It is not reduced by uric acid, creatinin, alcapton. 



(c) Phenyl hydrazin test. Place a small quantity of the dry 



substance (knife point), phenyl hydrazin hydrochlorate, 

 and two or three of acetate of soda in half a tube of 

 urine. If they do not dissolve, add a little water. Boil 

 30 minutes, then cool. Yellow crystals deposit. Under 

 the microscope they appear as yellosv needles. 



Quantitative Estimation. 



Precautions. -Remove any proteids that may present by 

 acidulating, boiling, and filtering. 



In performing a volumetric estimation with Fehling or Pavy's 

 modification it should be noted that the suboxide formed 

 may be re-oxidised by the oxygen of the atmosphere and 

 that in consequence a partial return of the blue colour may 

 be occasioned even during the performance of the process. 



