CRUCIBLE

an open, cup-shaped ve el or melting-pot used for melting ‘and calcining substances which need the application of extreme heat (metals, ores, minerals, gla , etc.). They must be made of some infusible, unbreakable f on: substance, such as clay, graphite. lime, aluminium, platinum, porcelain, or silver. The He ian C. (of fire-clay and coarse sand) is the commonest kind. For analytical purposes platinum and porcelain are much used. Lime or carbon Q’s. will withstand the highest temperatures. Also a hollow place at the bottom of a furnace to receive the melted metal. Figuratively, a test of the most decisive kind. A trying out or purifying test.