292 Y. KOGA & O. YAMAGATA. 



causes than mere segregation of silver have more or less influence on 

 the actual fineness of the finished coin, for some stages of the process 

 tend to lower the fineness by the oxidation of the metal, while other 

 stages act in an opposite way by taking away a part of the oxide 

 formed. 



II. Distribution of Silver on the Coin. 



The first series of experiments consisted in the endeavour to 

 discover the average fineness of the One Yen coin produced from 

 bars, of which the assay of granulation was known, and to examine 

 extent the of segregation by which different portions of the same coin 

 differed in composition. 



We selected four bars from four different melts named A, B, C, 

 and D, the granulation assays of which were carefully made. These 

 were rolled down to the required thickness as usual. Three blanks 

 were cut out from each of the fillets, one from the middle and one 

 from each end. These were marked respectively, A 2J A 15 A 3 ; B,, B„ 

 B,, &c. &c, the direction of lamination of the bar being carefully 

 marked on each blank. These blanks were then treated exactly the 

 same as the blanks for regular coinage. Care was taken in annealing to 

 place each of them among separate lots of ordinary blanks, so as not to 

 allow the effect of any accidental irregularity to fall simultaneously on 

 all of them. The loss of their weight in grains in annealing and 

 pickling is shown in Table I. 



