THE ART OF CASTING BRONZE IN JAPAN. 



643 



And as a comparison of the alloy "karakaue" with similar alloys of 

 other countries is of considerable metallurgical as well as historical 

 interest, I have given in Table III some analyses of several ancient 

 objects, which will enable tin's comparison to be made. 



I would also call your attention to a very valuable series of analyses 

 of oriental art metal work made under the direction of our chairman, 

 Professor Roberts-Austen, who has won special distinction for his 

 researches on alloys, and published by the science and art department. 



It will be seen from Table II that the presence of lead, as an impor- 

 tant constituent, is one of the characteristic features of the composi- 

 tion of the Japanese bronze " karakane," although, as is shown in 

 Table III, it is not peculiar to them. Several reasons have been 

 advanced for the origin of the iiresence of this metal in copi)er-tin 

 alloys 5 those, however, we need not divscuss here. One thing is cer- 

 tain, that even in very early times the relative properties of copper- 

 tin and copper-tin-lead alloys were known, as in almost all specimens 

 which have been analyzed swords and weapons in which strength and 

 hardness were essential consist of the former (copper-tin), and coins, 

 decorative objects, and figures, in which these properties were not 

 necessary, of the latter (copper-tin-lead). 



The wide range in the proportions of the constituents of "karakane" 

 is fully demonstrated by the analyses given above. This variability 

 in composition is not solely the result of attempts on the part of the 

 founder to produce si>ecial alloys, as might be conjectured, but is chiefly 

 owing to the practice, universally adopted, of mixing considerable 

 quantities of old metal "scrap" of unknown composition with the 

 furnace charge, even when the copper, lead, and tin of the same charge 

 have been carefully weighed in definite proportions, a practice not alto- 

 gether unknown in this country. In the case of the temple bronzes, it 

 is generally due to their having been cast from accunuilations of ex 

 voto offerings of the most heterogeneous character. 



A few words on the purity of the metals used by the Japanese in pre- 

 paring their alloys may not be out of place here. The copper, as will be 

 seen from the following analyses, is almost without exception extremely 

 free from the injurious metals — arsenic, antimony, and bisnuith: 



Japanese copper refined by native processes. 



Copper 



Lead 



Iron , 



Arsenic 



Antimony 



Silver 



Sulphur .. 

 Bismuth . . 



Total . 



Nobe-ji. 



99.30 

 .55 

 .10 



Trace. 



Trace. 

 .025 



Trace. 

 Nil. 



99. 975 



99.55 



.23 



.15 



Trace. 



:^ril. 



.009 



.03 



Nil. 



99. 969 



Omodani. 



99.80 



.12 



Trace. 



Trace. 



Nil. 



(a) 



Trace. 



Nil. 



Sumitomo 



(ma-buki- 



do). 



99.24 

 .49 

 .05 

 .04 



Trace. 

 .022 

 .01 

 Nil. 



99.92 



99. 852 



a Not determined. 



