SIK WILLIAM CROOKES ON SCANDIUM. 365 



Analysis. 



"037 gr. of scandium borate, treated in the manner described, gave 5 '27 7 gr. of 

 scandia, = 3'4173 gr. of scandium. 



Theory. Experiment. 



42-52 



57-48 



103-1 100-00 100-00 



SCANDIUM AUROCHLORIDE, 

 3ScCl :! ,2AuC] 3 ,2lH 2 O. 



Scandium aurochloride is prepared by mixing strong solutions of the component 

 chlorides, and allowing the mixture to evaporate slowly over sulphuric acid in a 

 vacuum desiccator. The double salt separates out in a felt-like mass of yellow 

 needle-shaped crystals, which are very deliquescent. In this state the salt has the 

 composition given above. The composition is unusual, but the analytical results 

 agree very well with it, and I have not succeeded in preparing a salt with different 

 proportions of the chief constituents. The water of crystallisation can be driven off' 

 gradually by careful heating. 



For analysis the felt-like mass of aurochloride was made as dry as possible by 

 pressing it several times between warm dry filtering paper until the paper was 

 uusoiled. 



Analysis. 



26717 gr. of scandium aurochloride, dried by pressure, were heated in an air-bath 

 to 100, and kept at that temperature for three hours. The aurochloride 

 melted to a clear orange-coloured liquid, solidifying on cooling to a crystalline 

 mass. The loss of weight after liquefaction was found to be 4"350 gr. 



After keeping the salt for several days at 100 the liquid gradually becomes solid 

 and crystalline, and in this state is anhydrous. The further loss of weight was 

 2'672 gr., equal to a total loss of 7'022 gr. 



The residue from which the water had been driven was dissolved in hot water 

 acidulated with hydrochloric acid, and sodium bisulphite was added. Gold com- 

 menced to separate at once, and on boiling the metal collected in a coherent sponge. 

 It was filtered, washed with dilute acid, and weighed after ignition. 



After separating the metallic gold, the filtrate was mixed with excess of ammonia 

 and boiled. The precipitated scandia was filtered, washed, ignited, and weighed. 



