Small Amounts of Sugar in Urine. 179 



ducing substance in question is glucose, although this has been 

 found difficult of positive proof. This question is being further 

 investigated. 



The method is carried out as follows: About 2 grams of dry 

 picric acid are added to 10 c.c. of urine in a test tube and the 

 tube vigorously shaken. The tube is now stoppered and placed 

 in an ice box at 0° C. After the tube has stood for an hour, it is 

 again shaken and then allowed to stand over night in the ice box, 

 after which the mixture is filtered through a small filter paper into 

 a dry test tube. The filtrate now contains less than 0.1 mg. of 

 creatinine per c.c, a quantity too small to invalidate the estimation 

 of the sugar. If the urine has reacted negatively to Benedict's 

 qualitative reagent, the filtrate is diluted 1-5 or 1-10 with sat- 

 urated picric acid solution. If the qualitative test has shown a 

 small amount of sugar, a greater dilution is made. The following 

 rule may be followed: for 0.1 per cent, of sugar dilute 1-5, for 

 0.2 per cent, dilute 1-10, for 0.3 per cent, dilute 1-15, etc. To 

 develop the color, pipette 3 c.c. of the diluted fluid into a tall, 

 narrow tube graduated to 10, 15 and 20 c.c, add 1 c.c. of saturated 

 sodium carbonate solution and heat in a beaker of boiling water 

 for 15 minutes. The tube is now thoroughly cooled and diluted 

 with water to the mark most satisfactory for colorimetric compari- 

 son. Either pure glucose in saturated picric acid or a standardized 

 picramic acid solution may be used as standard. 1 



Influence of the Ingestion of Glucose on the Sugar of the Urine 



Times 

 A. M.-P. M. 



Sugar of Blood, 

 Per Cent. 



Sugar of Urine, 

 Per Cent. 



Benedict's Qualitative Reaction 

 for Sugar in the Urine. 





0.12 



0.09"! 





9-10 



0.15 



0.10 > 



Negative 





0.17 



0.17 J 





IO-I I 



0.23 









0.22 



0.90 



Strongly positive 



11-12 



0.l6 



0.41 



Positive 





0.15 



0.32 



Slight cloudiness 



12- I 



0.14 









0.14 



0.27 



Slight cloudiness 



I- 2 



0.13 









0.13 



0.25 



Very slight cloudiness 



2- 3 



O.09 



0.17 



Negative 



1 See Myers and Bailey, J. Biol. Chem., 191O, XXIV, 150. 



2 75 grams of glucose by mouth at 9.15. 



