A series of discourses on the many functions of the ether of space. in this volume, Sir Oliver explains for the layman the functions of the ether of space and emphasizes its importance in the understanding of the physical universe. The author further hints that life and mind make use of the ether and that a knowledge of its properties must be essential to the philosopher. Contents: ether and its vibrations; fundamental notions about an ether; on waves; ether as transmitter of force; action at a distance; electricity and its action across space; magnetism; electromagnetism; matter as one of the forms of ether energy; life and mind and their use of the ether.