H. D. Minnig — Aluminium and Beryllium. 483 



Commercial acetyl chloride can not be used in this work 

 because of phosphorus compounds used in its manufacture, 

 the last of which cannot be removed. This phosphorus con- 

 • tamination shows itself not only in the filtrate from the alu- 

 minium precipitate, but also in the aluminium precipitate itself, 

 giving high results. The acetyl chloride was therefore pre- 

 pared as described in the former article.* Acetic anhydride 

 was distilled from a little anhydrous sodium acetate to remove 

 contaminating phosphorus compounds. Tests for included 

 phosphorus compounds were made by hydrolyzing the acetic 

 anhydride with water, evaporating down with nitric acid to 

 oxidize any trivalent phosphorus which might be present 

 from the manufacture of the commercial product, and treating 

 the solution with ammonium molybdate in nitric acid solution. 

 The purified acetic anhydride was then saturated with hydro- 

 gen chloride and the product distilled at 100° C. in a rapid 

 current of the same gas. Redistillation gives pure acetyl 

 chloride. 



The method of procedure was the same as in the separation 

 of iron from aluminium. Measured portions of solutions of 

 the two chlorides in small beakers were evaporated to the 

 smallest possible volume on the steam bath. In case the evap- 

 oration proceeds to dryness it is well in dissolving the salts to 

 add a drop of hydrochloric acid to prevent the formation of 

 basic salts, particularly of basic beryllium chloride. The 

 beaker containing the concentrated solution was then placed 

 in a dish of cold water and the acetone-acetyl chloride mixture 

 (4-1) was added drop by drop from a dropping funnel to the 

 complete precipitation of the hydrous chloride of aluminium. 

 Fifteen to twenty cubic centimeters of the 'mixture usually 

 sufficed. The settling of the crystalline precipitate is a good 

 indication, though not an infallible one, of the complete pre- 

 cipitation of the aluminium chloride. When the precipitation 

 was judged to be complete, the precipitate was transferred to 

 a weighed perforated platinum crucible and carefully washed 

 with the precipitating mixture. The filtrate and washings 

 were caught in a beaker under a bell jar. The precipitate was 

 dried slowly, at first high above a low Bunsen flame and then 

 gradually lowered until the full heat of the burner was obtained. 

 The hydrous chloride on ignition leaves the oxide. The ace- 

 tone-acetyl chloride solution of beryllium was copiously but 

 cautiously. diluted with water to avoid spattering, and the 

 resulting solution in a beaker covered by a watch glass, was 

 warmed gently on the steam bath until the volume seemed to 

 remain constant, indicating that the easily volatile acetone had 

 been removed. The solution was then boiled and ammonium 



*Loc. cit. 



