I

A soft silver solder for resoldering parts already soldered is made of silver, 3 parts; copper, 2 parts, and zinc, 1 part.

II

Silver, 1 part, and brass, 1 part; or, silver, 7 parts; copper, 3 parts, and zinc, 2 parts.

III

A readily fusible silver solder for ordinary work: Silver, 5 parts; copper, 6 parts, and zinc, 2 parts.

IV

(Soft.) Copper, 14.75 parts; zinc, 8.20 parts; silver, 77.05 parts.

V

Copper, 22.34 parts; zinc, 10.48 parts; silver, 67.18 parts.

VI

Tin, 63 parts; lead, 37 parts.

French Solders for Silver

I

For fine silver work: Fine silver, 87 parts; brass, 13 parts.

II

For work 792 fine: Fine silver, 83 parts; brass, 17 parts.

III

For work 712 fine: Fine silver, 75 parts; brass, 25 parts.

IV

For work 633 fine: Fine silver, 66 parts; brass, 34 parts.

V

For work 572 fine: Fine silver, 55 parts; brass, 45 parts.

Solder for Silversmiths, etc

Gold, 10 parts; silver, 55 parts; copper, 29 parts; zinc, 6 parts.

Hard Solder

Silver, 60 parts; bronze, 39 parts; arsenic, 1 part.

Soft Solder

Powdered copper, 30 parts; sulphate of zinc, 10 parts; mercury, 60 parts; sulphuric acid. Put

the copper and the zinc sulphate in a porcelain mortar, and then the sulphuric acid. Enough acid is required to cover the composition; next add the mercury while stirring constantly. When the amalgamation is effected, wash several times with hot water to remove the acid, then allow to cool. For use, it is sufficient to heat the amalgam until it takes the consistency of wax. Apply on the parts to be soldered and let cool.