424 Dr. Genth's Contributions to Metallurgy. 



No. 3. Tschen. — Thick brass-yellow coin, very good cast of 

 fine grain ; not easily tarnishing. Sp. grav. at 25° Cels. = 8-497. 

 It contains — 



Copper = 55-53 per cent. 



Tin = 0-33 



Antimony = 3-21 „ 



Arsenic =3-44 „ 



Lead = 103 



Zinc =: 32-74 



Nickel = 0-54 



Iron = 2-38 „ 



99-20 

 No. 4. Tschen. — Brass-yellow with a greenish tinge, a very 

 good cast ; fine grain, brittle ; easily tarnishing. It contains — 



Copper = 59'14 per cent. 



Tin = 2-71 



Lead = 3-40 



Zinc =29-62 



Iron = 4*83 „ 



Nickel = 0-17 



Cobalt and Silver . . . = traces 



99-87 

 No. 5. Tschen. — Bronze-yellow, greyish on the fresh fracture. 

 Spec. grav. =8-552. It contains — 



Copper . . . . = 59-983 per cent, (from the loss). 



Tin = 1-204 



Silver = 0-068 



Lead = 3-977 



Zinc = 32-114 



Nickel = 0-552 



Iron = 2-102 



Arsenic .... = trac e 

 100-00 

 No. 6. Tschen. — Colour bronze-yellow, the fresh fracture 

 brass-yellow; the grain is coarse and crystalline, with many 

 cavities ; did not fill the mould well ; very brittle. Spec. grav. 

 = 8-166. Tt contains — 



Copper =60-19 per cent. 



Tin = 1-81 



Lead = 5-83 „ 



Zinc =31-57 



Iron = 1'34 „ 



100-74 



