On the Liquation of certain Alloys of Gold. 21 



race, proceeded westward from its early home in the east is a fair 

 subject for speculation. But, under any circumstances, this dis- 

 covery aids in bridging over the interval between palaeolithic man 

 in Britain and in India, and adds another link to the chain of 

 evidence by which the original cradle of the human family may 

 eventually be identified, and tends to prove the unity of race between 

 the inhabitants of Asia, Africa, and Europe, in Palaeolithic times. 



" On the Liquation of certain Alloys of Gold." By EDWARD 

 MATTHEY, F.S.A., F.C.S., Assoc. R.S.M. Communicated by 

 Sir G. G. STOKES, Bart., F.R.S. Received April 14, 

 Read May 7, 1896. 



The molecular distribution of the metals in alloys of gold and of 

 metals of the platinum group has been described by me at some 

 length, in a series of papers which have already been published by the 

 Royal Society.* New interest in the subject has, however, arisen in 

 connexion with the extraordinary development in various parts of the 

 world especially in South Africa, of certain processes which are now 

 employed for extracting gold from its ores. Their use has been 

 attended with the introduction into this country of a series of alloys 

 of gold and the base metals which have hitherto rarely been met 

 with in metallurgical industry. The base metals associated with the 

 gold in these cases are usually the very ordinary ones lead and zinc, 

 but their presence in the gold has given rise to unexpected difficul- 

 ties, as the distribution of the precious metal in the ingots which 

 reach this country is so peculiar, that it is not possible to estimate 

 the value of the ingots by taking the pieces of metal required for 

 the assay, by any of the well-known methods now in use. 



The grouping of the metal in these ingots presents much scientific 

 as well as industrial interest, and the following is a brief state- 

 ment of the facts which have been observed. r 



A. An ingot of gold weighing 3'545 kilograms was assayed with a 

 view to subjecting it to the ordinary operation of refining. A piece 

 of metal was, therefore, cut from the base of the ingot at the point 

 marked A, and the following are the results of four assays made 

 on this piece of metal : 



Gold 1 665-8 



2 663-6 



3 662-4 



4 658-0 



Average 662'45 



* ' Phil. Trans.,' A, vol. 183 ; p. 629, 1892. ' Boy. Soc. Proc.,' vol. 47, p. 180, 1890. 



