0^ 



40 



20% solution of caustic potash in a test tube and add a 

 pinch of subnitrate of bismuth. Boil the mixture and 

 if glucose be present the powder turns black. Albumin 

 and sulphur also reduce bismuth and must be removed if 

 the test is to be reliable. Bismuth is more or less black- 

 ened with normal horse urine. 



Ny lander's Reagent. A solution is made of bismuth 

 subnitrate 2 grams ; Rochelle salts 4 grams ; potassium 

 hydroxide 10 grams; and distilled water to 100 cc. The 

 urine is heated to boiling and a few drops of this alkaline 

 solution of bismuth added, and on continuing the boiling, 

 if sugar be present, the mixture turns black. The test is 

 delicate, as little as 0.025% of glucose can be detected. 



Phenylhydrazine Test. (Modified from Kowarsky). 

 To 5 drops of pure phenylhydrazine and 10 drops of 

 glacial acetic acid in a test tube is added 1 cc. of a 10% 

 solution of sodium chloride. After shaking the mixture, 

 3 cc. of the urine are added and the test tube heated for 

 two minutes or longer. The fluid is then allowed to cool 

 slowly. If the sugar contents exceed 0.5% the precipitate 

 of glucosazone takes place in about two minutes. Small 

 quantities of albumin do not hinder the reaction, but are 

 precipitated by boiling. After an hour or more examine 

 the precipitate microscopically. A 10 9r solution of sodium 

 hydroxide has been recommended as a substitute for the 

 sodium chloride solution and greater delicacy is claimed 

 for the reaction. 



The glucosazone crystals will have the form typical 

 of skeins of wool, which will generally be double, whereas 

 other crystals precipitated, such as those of glycuronic 

 acid, are irregularly formed. As little as 0.005 7f (one- 

 fortieth grain per ounce) of glucose can be detected in 

 urine by the phenylhydrazine reaction. 



Uric acid, urea, xanthine, and creatinin in no way 

 simulate the reaction of glucose with phenylhydrazine. 

 The only bodies which can offer confusion are glycuronic 

 acid and its derivatives. 



FermentationTest. Robert 'sDifferentialDensity Method. 

 Take the specific gravity of the urine before adding the- 



