chemical vessel made of earth, and so tempered and backed as to endure the greatest fire. They are used to melt metals, and to flux minerals, ores, &c.

The figure of a crucible is commonly that of an obtuse conoid, with its base at the top, and obtuse apex at the bottom; whence this conical figure may be varied, till it comes to the hollow segment of a sphere.

The crucibles most generally used are those of Hesse and Austria.