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



Residue A. Solution B. 



The residue A was heated with hydrochloric acid to which a small 

 quantity of nitric acid was added from time to time ; the solution was 

 diluted and filtered. 



Residue C. Solution D. 



Residue G. Dried and heated 0*5 gram in the oxyhydrogen flame. 

 The lines of gallium, chromium, nickel, and iron are strong, and lines 

 of sodium, manganese, potassium, copper, and silver are also present. 



Solution J3. Boiled for two hours with part of the finely powdered 

 sample added gradually to neutralise all the free acid, so that the 

 gallium in the solution might be precipitated as a basic salt.* The 

 solution was decanted and filtered. The residue was boiled with 

 solution D, to which the remainder of the finely powdered sample 

 was slowly added ; after boiling for several hours the solution was 

 filtered, and the residue F washed with water. The filtrate was 

 mixed with that from solution J>, the mixture forming solution G, 

 which should be free from gallium. This solution was boiled with 

 freshly precipitated copper hydrate,! and the precipitate examined 

 spectrographically for gallium. It contained none. 



Residue F. Boiled with an excess of hydrochloric acid, diluted, 

 filtered, and washed, Residue H. Filtrate I. 



Residue H. Dried, powdered, and mixed with residue C. Gentty 

 heated, the mixture decomposes and expels hydrocarbons, causing 

 the mass to ignite and evolve some white fumes. The substance 

 was thus seen to be very inflammable, and the temperature was 

 reduced as quickly as possible. When cold, it was covered with 

 aqua regia and heated on the water bath for several hours, then 

 diluted and filtered. Filtrate added to J, forming solution K. 

 Residue L. 



Residue L. A small quantity of it was heated in the oxyhydrogen 

 flame. The gallium line is strong. 45 c.c. of strong sulphuric acid 

 was heated in a porcelain basin until it gave off white fames; the 

 residue was then added forming a pasty mass which was kept hot for 

 about three hours ; white fumes being emitted during the whole time. 

 Water was then added, and the liquid filtered. Filtrate N. Resi- 

 due M. A portion of the latter was heated in the oxyhydrogen flame. 

 The gallium line is still present. 



Besides the small quantity remaining in the residue M, the gallium 

 should now be in the solutions K and N. Solution K was evaporated 

 nearly to dryness to expel the excess of acid, then diluted, saturated 

 with sulphur dioxide, nearly neutralised with ammonia, and boiled to 



* ' Comptes Rendus,' vol. 93. p. 818. See also a complete account, ' Separa- 

 tion du Gallium d'avec les autres elements,' par M. Lecocq de Boisbaudran. Paris, 

 Oautbier- Villain. 1884. Reprinted from the ' Annales de Chimie,' 6. Serie, t. 2. 



f ' Comptes Rendus,' vol. 94, p. 1154. 



