Browning and TJhler — Gallium-Indium Alloy. 351 



Art. XXYI. — On a Gallium-Indium Alloy; by Philip E. 

 Browning and Horace S. IThler. 



[Contribution from the Kent Chemical and the Sloane Physical Labora- 

 tories of Yale University.] 



A few months ago Mr. F. G. McCutcheon, chemist of the 

 Bartlesville Zinc Company, observed some mercury -like globules 

 upon the surface of a leacly residue from the distillation of 

 zinc. The appearance of these globules seemed to be due to 

 the fact that the residue had been stored away in a warm 

 place, and the phenomenon suggested to the observer the sub- 

 jection of the residue to a sweating process. This treatment 

 resulted in a more abundant separation of the peculiar material, 

 which, from the character of its source and its low melting 

 point, suggested the element gallium. It proved to be essen- 

 tially an alloy of that element with indium.* 



Through the kindness of the manager, Mr. K. Stock, and 

 the chemist of the Company, we have been supplied with sev- 

 eral grams of the alloy and a considerable amount of theleady 

 residue. Rough analyses of these products show the gallium- 

 indium alloy to contain about 10 per cent of indium, with 

 small amounts of zinc and lead, and spectrographic traces of 

 copper and silver. The leady residue contains about 95*6 per 

 cent of lead, a fraction of 1 per cent of copper, about 3 per cent 

 of gallium and indium together, and about 1*2 percent of zinc. 



The alloy is not very vigorously attacked by the common 

 acids, especially by nitric acid, nor by potassium or sodium 

 hydroxide, although all of these reagents act upon it more or 

 less, especially upon warming. Aqua regia dissolves it very 

 readily. . From a solution of the alloy the hydroxides of 

 gallium* and indium may be precipitated together by ammo- 

 nium hydroxide in the presence of ammonium chloride, — a 

 method of separation from zinc first worked out by Lecoq de 

 Boisbaudran.f 



Other procedures suggested by him are the separation of 

 gallium from indium by treating a solution containing them 

 with potassium or sodium hydroxide in excess, which dissolves 

 the gallium hydroxide,^ — a method followed by us with fair 

 success; and the separation from aluminium, chromium and 

 beryllium, elements which form a group with gallium because 

 their hydroxides are not only precipitated by ammonium 

 hydroxide in the presence of ammonium chloride, but are 

 soluble in sodium or potassium hydroxide, the separation being 

 accomplished by making the alkaline solution of the hydroxides 



* Hillebrand and Scherrer, Jour. Indust. and Eng. Chem., viii, 225. (This 

 article appeared after our paper had gone to press — authors.) 

 fCompt. rend. (Paris), xciv, 1628. Jlbid., xcv, 410. 



