ALLOYS. GOLD, SILVER, ETC.
Gold alloys. Standard gold for coin in Great Britain i,: Pure gold, 22; pure copper, 2. This alloy is harder and more fusible but less ductile than pure gold. It is said to be 22 carats fine. Standard gold for coin in United States and France: Gold, 9; copper, 1. Jeweler's gold varies from 22 down to 9 parts gold, with sufficient silver, or copper and silvet, to make up 24 parts. The number of parts of pure gold in 24 parts of an alloy denotes its fineness; thus gold 18 carats fine is an alloy containing 18 parts of pure gold and 6 parts silver or copper.
Siii.or alloys are as follows: Sta udard silver for coin and plate in Great Britain: Pure silver, 222; pure copper,18. Specific gravity, 10.2.) French standard silver f or medals and plates : Silver, 95; copper, 5. ..kmerican and French standard sil ver for coin: Silver, 90; copper, 10. French standard silver for jewelry work: Silver, 80; copper, 20. Silver solder: Silver, about 66 per
cent., with zinc and copper.
Queen's . Tin, 9; antimony, 1; lead, 1; bismuth, 1. 1Tsed for teapots, spoons, etc.
Brass is made of copper, 64 parts; zinc, 36 parts; proportions slightly varied to make the metal darker by increasing the copper even to 74 per cent.
• Bronze is made of copper, 85 to 90 parts; tin, 10 to 15 parts; sometimes a little lead and zinc is added.
! Bell metal is made of copper, 75 parts, and tiu, 25 parts.
I German, silver is made of copper, 16 parts; zinc, I 7 parts, and nickel, 8 parts.
Type metal is made of lead, 83 parts; metallic antimony', 7 Darts.
treqy pin g metal is made of lead, 9 parts; metallic antimony and bismuth, each 2 parts.
Common solder is made of lead and tin equal parts.
Fi nt made of lead, 1 part ; tin, 2 parts.
Pewter is made of lead, 4 parts; tin, 1 part.