Under present-day conditions in science, the acceptance of the ordinary doctrine of transmission across space involves likewise the acceptance of the existence of an ethereal substance which pervades all space and forms the medium by which such transmission is carried out. The properties of this medium are, of course, precisely adapted to its assumed function of transmission. These properties it is not necessary to discuss, for when the existence of the transmission itself has been finally disproved, the necessity for the transmitting medium clearly vanishes. PART I GENERAL STATEMENT 1. _Advantages of General View of Natural Operations_ The object of this statement is to outline and illustrate, in simple fashion, a broad and general conception of the operation and interaction of matter and energy in natural phenomena. Such a conception may be of value to the student of Nature, in several ways. In modern times the general tendency of scientific work is ever towards specialisation, with its corresponding narrowness of view. A broad outlook on Nature is thus eminently desirable. It enables the observer to perceive to some extent the links uniting the apparently most insignificant of natural processes to those of seemingly greater magnitude and importance. In this way a valuable idea of the natural world as a whole may be gained, which will, in turn, tend generally to clarify the aspect of particular operations. A broad general view of Nature also leads to the appreciation of the full significance of the great doctrines of the conservation of matter and energy. By its means the complete verification of these doctrines, which appears to be beyond human experiment, may be traced on the face of Nature throughout the endless chain of natural processes. Such a view also leads to a firm grasp of the essential nature and qualities of energy itself so far as they are revealed by its general function in phenomena. 2. _Separate Mass in Space_ In the scheme now to be outlined, matter and energy are postulated at the commencement without reference to their ultimate origin or inherent nature. They are accepted, in their diverse forms, precisely as they are familiar from ordinary terrestrial experience and phenomena.