As knowledge increases, the attitude of science towards the things of the invisible world is undergoing considerable modification. Its attention is no longer directed solely to the earth with all its variety of objects, or to the physical worlds around it; but it finds itself compelled to glance further afield, and to construct hypotheses as to the nature of the matter and force which lie in the regions beyond the ken of its instruments. Ether is now comfortably settled in the scientific...
