398 Prof. W. N. Hartley and Mr. H. Ramage. 



The various precipitates of basic acetates were mixed, with the 

 exception of that from 7, which contained no gallium. In order to 

 separate phosphoric acid, the precipitates were fused with about 

 three times their weight of mixed carbonates. Some potassium 

 nitrate was added towards the end of the fusion, to convert chromium 

 into chromates. The heavy metals were left as oxides or carbonates, 

 the phosphoric acid going into solution. After extraction with hot 

 water, the solution was filtered. 



Filtrate L. Residue M. 



Coloured greenish by man- Dried and fused in a silver dish 



ganates, boiled -with a few drops with caustic soda to dissolve 

 of alcohol to separate manganese gallium hydroxide. Extracted 

 as hydroxide. Solution, after with water and filtered. Residue 

 again filtering from manganese, not examined further. Solution : 

 was yellow from chromates. acidified with HC1 and ammo- 



nium chloride and ammonia 

 added. The precipitate was fil- 

 tered off, dissolved in HC1, and 

 sparked to observe its spectrum. 



These gallium spectra showed that there were still traces of 

 chromium in the gallium chloride, and from this the gallium was 

 purified completely by precipitation in a strongly acid solution with 

 potassium ferrocyanide and subsequent removal of the iron by treat- 

 ment with sodium hydrate, according to the method of Lecocq de 

 Boisbaudran.* 



The foregoing description of the analytical details proves the 

 presence of gallium in the metal, and gives a clear indication of how 

 it may be separated by a simple process. 



In subsequent operations on the blast-furnace metal, the ferrous 

 chloride was mixed with calcium carbonate, and the gallium was 

 found to be all precipitated and capable of easy separation 'from the 

 calcium salt.f Latterly it was found i.o be more convenient to boil 

 the acid solution containing gallium with an excess of the iron under 

 examination, and thus the gallium is concentrated in the residue 

 T?hich remains un dissolved.;]: 



It became necsssary to consider what was the source of the gallium 

 contained in the iron. Was the gallium concentrated in the metal ? 

 Or did it pass into the slag of the converter? Was it originally con- 

 tained in the ore, the lime, or the fuel ? Was it easily volatilised, so 

 as to pass off with fume or with flue dust ? 



* ' Comptes Rendus,' vol. 94, p. 1228. 



t Loc. cit., p. 1629. 



| ' Comptes Rendus,' vol. 49, p. 1625. 



