The Probert Encyclopaedia of Science & Technology

EARTHS

Earths is a term applied to certain tasteless, inodorous, dry, uninflammable, nonvolatile, insoluble substances, difficultly fusible, and of a moderate specific gravity, which constitute by far the greatest part of the gravel and soil that go to make up the mountains, valleys, and plains of our globe. They include lime, baryta, strontia, magnesia, alumina, etc. The earths were regarded as simple bodies until Sir Humphry Davy proved them to be compounds of oxygen with metals.
Research Earths