On the Liquation of certain Alloys of Gold. 23 



Three assays at b bottom of ingot^ 



Gold. Silver. 



1 332-5 0181 



2 652-0 0-095 



3 410-5 0-057 



And seven assays were made from a " dip," viz. 



Gold. Silver. 



1 622-0 



2 574-4 0-072 



3 653-5 0-011 



4 623-2 



5 580-0 0-138 



6 603-3 



7 . 562-3 



Average of the whole number 



of the assays made .... 576*2 0'090 



It became evident, therefore, that the only method of determining 

 the true quality of this ingot consisted in actually separating the 

 gold and silver in mass, and this was effected by dissolving in nitro- 

 hydrochloric acid, the silver being recovered as chloride and reduced 

 to metallic silver, and the gold precipitated by iron chloride as pure 

 metallic gold. 



The result of this operation yielded 



Gold 7-504 kilograms. 



Silver 0-928 



which showed that the standard fineness of the ingot was 



Gold 614-0 



Silver 75'8 



and its true value 1,028 ; while the value, as calculated from the 

 average of the assays previously made, 



Gold 576 



Silv-r 0-090 



would have been only 965. 



Analysis proved that the metals present other than gold were 

 as follows : 



