1912] Lipman-Sharp : Phenoldisulphonic Acid Method 29 



tain if such materials in any way affect the accuracy of the 

 determination. Indeed Chamot and his coworkers have recom- 

 ■ mended the use of aluminum cream for removing suspended 

 material from the solution, and claim to have had very satis- 

 factory results in the use of that material. Our experiments 

 in this series were intended to clear up this question and the 

 following results show very strikingly that none of the materials 

 mentioned may be employed in the nitrate determinations with- 

 out incurring very serious losses. Table V gives results obtained 

 in the use of potash alum, and Table VI gives results obtained 

 in the use of bone black and aluminum cream. 



