ARCHIBALD-FULTON] ESTIMATION OF IRON 253 



2. The precipitate is slightly soluble in the wash water. 



3. If corrections are applied for these solubilities, the determin- 

 ation of iron by this method becomes very exact. 



4. Iron can be separated from manganese in a solution containing 

 four times as much manganese as iron, the amount of manganese 

 carried along with the precipitate being inappreciable for most pur- 

 poses. This amount increases with the acid dilution of the mother 

 liquor. The presence of ammonium chloride to the extent of 5 grams 

 in 100 cc. of solution is an advantage in this separation. 



Chemical Laboratory, University of British Columbia, Vancouver, B.C. 



