APPARATUS. 335 



tical position, wait a moment or two, and if the reduc- 

 tion of the copper be complete, the sediment will sink 

 in a very short interval of time, to the bottom of the 

 tube ; and if care has been taken not to overdo the thing, 

 i. e., introducing more than was necessary from the 

 burette, the analysis is completed and the burette may 

 be read. 



Now the 100 grains of the standard solution in the 

 test tube would require j- grain of sugar for its reduc- 

 tion, and 50 grains of the solution in the burette will 

 contain | grain of sugar. The burette should therefore 

 be lead at 50. The student is advised to repeat the 

 operation several times until he shall have become 

 familiar with the reactions. The quantity of test solu- 

 tion is ample for this. If, after satisfactory trials, it 

 shall be found that the standard solution is to strong or 

 too weak, water or copper may be added to the copper 

 solution without making any change in that of the 

 caustic, and the test should again be repeated. 



Analysis of Urine for Sugar. Prepare the standard 

 solution for use just as has been directed; i. e. 9 measur- 

 ing 66 grains of the caustic solution, and adding the 

 copper solution to make the volume of 100 grains. 

 Pour, as before, into the largest test tube, rinsing the 

 measuring bottle, adding the " wash " to the contents 

 of the tube. A very little clear water may also be added 

 to the tube. Fill the burette to the " " mark with 

 the urine to be analyzed, bring the test tube over the 

 spirit lamp, and heat to ebulution. Now go on and 

 tritate just as directed in the preceding test, observing 



