IvUNGE'S NITROMETER 



415 



holding the nitric compounds in solution. The chlorin is not re- 

 moved from the dry residue of the evaporated water, as its pres- 

 ence in moderate quantity does not interfere with the accuracy 

 of the process. In order to obtain the amount of nitrogen in the 

 form of nitrates, the total volume of nitric oxid must be dimin- 

 ished by that due to nitrites present, which must be determined in 

 a separate analysis. The method of manipulation is given in the 

 following paragraph. 



361. Lunge's Nitrometer. The apparatus employed by Noyes, 

 in a somewhat more elaborate form, is known as Lunge's nitrom- 

 eter.* 9 This apparatus is shown in Fig. 28. It consists of a 



Fig. 28. lounge's Nitrometer. 



burette a, divided into one-fifth cubic centimeters. At its upper 

 end it is expanded into a cup-shaped funnel attached by a three- 

 way glass stop-cock. Below, the burette is joined to a plain tube 

 b, of similar size, by means of rubber tubing. The apparatus is 

 first filled with mercury through the tube b, the stop-cock being 

 so adjusted as to allow the mercury to fill the cup at the top of a. 

 The cock is then turned until the mercury in the cup flows out 

 49 Berichte der deutschen chemischen Gesellschaft, 1878, 1 1 : 437. 



