296 



T. KOGA & O. YAMAGATA. 



Fig. 4. 

 Blank C,. 



I. 



II. 



III. 



IV. 



V. 



VI. 



VII. 



8980 8988 80S 2 " 



899-6 809-6 89D-6 



901-1 900-9 901-0 900-8 



9025 902 7 9020 9012 1)01 9 9020 



S00-5 . 900-6 900-9 899'9 



8997 899-5 S99 5 



"\ 898-9 899-5 898 8 . 



C x . C 2 . C 3 . 



Average of all assays. 900*617 900*787 900-331 



Highest assay. 903*2 903-0 902-7 



Lowest assay. 898*6 898-1 898*2 



Difference between highest 



and lowest assays. 4*6 4*9 4*5 



The preceeding results furnish fresh illustrations of the well 

 known fact, that, in an ingot made of the alloy containing 900 per 

 mille of silver and 100 of copper, there is a segregation or concentra- 

 tion of silver towards the central line of the ingot. The middle 

 portions in such an ingot contain the highest proportions of silver, 

 while copper predominates along the edges. We observe in the blanks 

 under .examination that this difference may be as much as 4*9 per 

 mille, as in blank C,. It is also to be, observed that even adjacent 

 parts lying in the same line may show a considerable difference in 

 composition, which is probably due to several causes. We may, 

 however, regard each of the strips which we have prepared as of one 

 fineness by taking the mean of all the assays made from it. Taking 



