82 G. Edgar — Estimation of Iron and Vanadium. 



70°-80° and the titration completed at that temperature. The 

 solution, having now a volume of 100-150 cm3 , was passed 

 through a column of amalgamated zinc in a long Jones reductor, 

 being preceded by 150 cm3 of hot dilute (2-J per cent) sulphuric 

 acid and followed by 100 cm3 of dilute acid and finally 200 cm3 of 

 distilled water. The receiving flask, containing an excess of 

 ferric sulphate, was kept cool by means of running water, and 

 its contents, after the addition of sirupy phosphoric acid to 

 remove the color of the iron, were titrated with permanganate 

 until the color had changed from bluish green to yellow, 

 and the color of the permanganate began to be persistent and 

 destroyed only by shaking. The flask was then heated to 70°- 

 80° and the titration completed in the hot solution. 



The results given in the table show that iron and vanadium 

 may be readily estimated in the presence of each other by two 

 oxidations with potassium permanganate, following reduction 

 first with sulphur dioxide and last with amalgamated zinc, 

 under the conditions described above. 



In conclusion, the author desires to thank Prof. F. A. Gooch 

 for advice given in the course of the work. 



