III.—Vanino’s.—Sixty parts, by weight, of strontium thiosulphate; 12 parts, by weight, of a 0.5 per cent acidified alcoholic solution of bismuth nitrate; 6 parts, by weight, of a 0.5 per cent alcoholic solution of uranium nitrate. The materials are mixed, dried, brought gradually to a temperature of 2,372° F., and heated for about an hour. The phosphorescence is emerald green.
IV.—Balmain’s.—Twenty parts, by weight, of calcium oxide (burnt lime), free from iron; 6 parts, by weight, of sulphur; 2 parts, by weight, of starch; 1 part, by weight, of a 0.5 per cent solution of bismuth nitrate; 0.15 parts, by weight, of potassium chloride; 0.15 parts, by weight, of sodium chloride. The materials are mixed, dried, and heated to 1,300° C. (2,372° F.). The product gives a violet light.
To make these phosphorescent substances effective, they are exposed for a time to direct sunlight; or a mercury lamp may be used. Powerful incandescent gas light also does well, but requires more time.
Paints For Metal Surfaces:
Blackening Ornaments Of Iron.
II.—This process protects the iron from rust for a long time. The treatment consists in coating the objects very uniformly with a thin layer of linseed-oil varnish, and burning it off over a charcoal fire. During the deflagration the draught must be stopped. The varnish will first go up in smoke with a strong formation of soot, and finally burn up entirely. The process is repeated, i. e., after one coating is burned off a new one is applied, until the parts exhibit a uniformly handsome, deep-black color. Next, wipe off the covering with a dry rag and heat again, but only moderately. Finally, the articles are taken from the fire and rubbed with a rag well saturated with linseed-oil varnish. The black turns completely dull, and forms a real durable covering for the objects.
Black For Polished Iron Pieces.
Glossy Black For Bicycles, Etc.—
| Amber | 8 ounces |
| Linseed oil | 4 ounces |
| Asphaltum | 1 1/2 ounces |
| Rosin | 1 1/2 ounces |
| Oil turpentine | 8 ounces |
Heat the linseed oil to boiling point, add the amber, asphaltum, and rosin, and when all melted remove from the fire and gradually add the turpentine.