OK MKTAI.S CONSIDKRKI) IN HKLATION TO TIIK I'KRIODIC LAW. 349 



precipitated were rejected, the middle portion being carefully washed with hot hydro- 

 chloric acid of sp. gr. 1*1, afterwards melted, with the addition of bisulphate of 

 potash, in a clay crucible and cast in a stone mould. 



There are other methods of obtaining pure gold, which are, in some respects, more 

 simple, and the best of these is, perhaps, that which involves the precipitation of 

 gold from its chloride by the passage of a stream of pure sulphurous anhydride. 

 The author believes, however, that the method above described is the most trust- 

 worthy, a view which is confirmed by Messrs. HOFMANN and KRUSS, who, in a recent 

 paper,* state the results of submitting to a careful examination certain methods 

 employed for separating gold from other metals, and they conclude that oxalic acid 

 is the best reagent for separating gold from platinum, which was the metal the 

 presence of which the author was most anxious to avoid. In discussing the results 

 obtained by Messrs. HOFMANN and KRUSS, Mr. W. BETTELt points out that for large 

 quantities of gold sulphurous anhydride is not a suitable precipitant. 



LIEBIO'S Annalen,' vol. 238, 1887, p. 66. 

 t ' Chemical News,' vol. 56, 1887, p. 133. 



