Dr. Genth's Contributions to Metallurgy. 425 



No. 7. Patec. — Not homogeneous, but a mixture of a grey 

 and pale copper-red alloy ; full of very small cavitieSj cuts easily 

 with the knife; brittle. Spec. grav. =8-517. It contains — 



Copper = 59*88 per cent. 



Tin = 7-90 „ 



Lead =31-42 „ 



Zinc = 0-59 „ 



Nickel = 0-18 „ 



Iron = 0-35 „ 



Silver, Arsenic, and Antimony = traces 



100-32 



No. 8. Patec. — Similar to No. 7, but of a coarser grain. 

 Spec. grav. above 9. It contains — 



Copper = 51*20 per cent. 



Silver = 0-03 „ 



Tin = 4-81 „ 



Lead = 42-25 „ 



Cobalt = 0-23 „ 



Iron = 1-36 „ 



Zinc and Nickel . . . = traces 



99-88 



From these analyses it is difficult to come to any general 

 conclusions, because the Chinese are not guided by certain and 

 invariable rules in the manufacture of their coins, although they 

 generally use a composition which might pass under the name 

 " brass.'' This brass is certainly made by mixing copper and 

 zinc together, and only seldom directly from the ore as the 

 ancients did. We know, from the descriptions given by 

 Father Mailla and J. F. Davis, that they make zinc, and also 

 know that long before the manufacture of zinc came into use in 

 Europe, the Dutch brought it from China. The copper which 

 is used for their coins appears to be always very impure, and 

 is evidently made from ores containing iron, sometimes with 

 small quantities of nickel and cobalt; analyses Nos. 3 and 7 

 indicate the occurrence of antimonial and arsenical grey copper 

 (tctrahedrite) in China. It seems that the Chinese frequently 

 take at hap-hazard whatever alloys and metals they can get, melt 

 them together, and cast their coins from the mixture. We have 

 seen, above, that alloys of copper and tin are frequently used in 

 China : now it seems that they add invariably a small quantity 

 of such alloys for the manufacture of their coins, because every 

 analysis shows the presence of tin ; we know, however, that ores 

 ofcoppcr, containing tin at the same time, arc not frequently met 

 with. 



