The oxides and acids of antimony give a clear and colorless bead while hot, and white after cooling.
Vanadic acid is absorbed by the charcoal, although it is not reduced.
Tungstic acid gives a dark yellow clear bead while hot, but is opaque and yellow when cold.
The oxides of manganese give to the soda bead a fine characteristic green color. This is the case with a very small quantity. This reaction is best exhibited on platinum foil.
Oxide of cobalt gives to the bead while hot a red color, which, upon being cooled, becomes grey.
The oxide of copper gives a clear green bead while hot.
The oxide of lead gives a clear colorless bead while hot, which becomes, upon cooling, of a dirty yellow color and opaque.
The following metals, when they are fused with soda on charcoal, in the flame of reduction, produce volatile oxides, and leave an incrustation around the assay, viz. bismuth, zinc, lead, cadmium, antimony, selenium, tellurium, and arsenic.
Bismuth, under the reduction flame, yields small particles of metal, which are brittle and easily crushed. The incrustation is of a flesh color, or orange, when hot, but gets lighter as it cools. The sublimate may be driven about the charcoal from place to place, by either flame, but is finally dissipated. While antimony and tellurium, in the act of dissipation, give color to the flame, bismuth does not, and may thus be distinguished from them.