4. “On Baryte: a Rare Form,” by Sir J. Hector.
This specimen was handed to Sir J. Hector by Major-General Schaw. It is a nodular variety, known as “Bologna stone,” and is composed of sulphate of baryta, or heavy spar. It commonly occurs in differently-formed crystals, and is used as a substitute for white-lead, and also in sugar-refining. This particular form is remarkable for its brilliant phosphorescence after heating with charcoal. Bologna phosphorus was made by powdering this material and cementing the powder with gum. The locality is the glauconitic marls, inland of Akiteo.