OPERATION OF THE REDUCTOR 



175 



centimeters of distilled water and 10 of strong sulfuric acid. 

 The flask is covered with a watch-glass and heated until the solu- 

 tion of the wire is complete. A sufficient amount of the strong 

 solution of potassium permanganate is added to oxidize the iron 

 and destroy the carbonaceous matter, avoiding however any ex- 



Fig. 9. Reductor and Filter Attachment. Fig. 10. Permanganate Burette. 



(Courtesy of A. H. Blair and J. B. Lippincott Co.) 



cess which would cause a precipitate of manganese dioxid. If 

 any precipitate is formed it is redissolved by adding a very few 

 drops of sulfurous acid and boiling until every trace is removed. 

 After cooling 10 cubic centimeters of dilute ammonia are added 

 and the solution passed through a jones reductor. 



152. Operation of the Reductor. Everything in connection 

 with the reductor should be clean and proved to be in good order 

 by previous treatment with dilute sulfuric acid and washing with 



