What Do We Know about the Deeper Layers of the Earth?

In the last twenty years modern chemical and physical methods have done much to extend our knowledge of the Earth. Some new questions have been raised, e.g. the question of the bonding relationships in the Earth's interior, which make the Earth an interesting object of research to chemists as well. This progress report attempts to give a survey of the Earth's structure as seen at the present day. Naturally, special emphasis has been placed on those aspects which concern the chemist.