Amalgams For Mirrors

I

Tin, 70 parts; mercury, 30 parts.

II

For curved mirrors. Tin, 1 part; lead, 1 part; bismuth, 1 part; mercury, 9 parts.

III

For glass balls. Tin, 80 parts; mercury, 20 parts.

IV

Metallic cement. Copper, 30 parts; mercury, 70 parts.

V

Mirror metal.—Copper, 100 parts; tin, 50 parts; Chinese copper, 8 parts; lead, 1 part; antimony, 1 part.

Reflector Metals

I. — (Cooper's.) Copper, 35 parts; platinum, 6; zinc, 2; tin, 16.5; arsenic, 1. On account of the hardness of this alloy, it takes a very high polish; it is impervious to the effects of the weather, and is therefore remark-

ably well adapted to the manufacture of mirrors for fine optical instruments.

II

(Duppler's.) Zinc, 20 parts; silver, 80 parts.

III

Copper, 66.22 parts; tin, 33.11 parts; arsenic, 0.67 part.

IV

Copper, 64 parts; tin, 32 parts; arsenic, 4 parts.

V

Copper, 82.18 parts; lead, 9.22 parts; antimony, 8.60 parts.

VI

(Little's.) Copper, 69.01 parts; tin, 30.82 parts; zinc, 2.44 parts; arsenic, 1.83 parts.