40 ORGANIC EVOLUTION CONSIDERED 



tween bodies are carried on. This, then, is its func- 

 tion — to act as the transmitter of motion and energy."* 



"As far as we know, it appears to be a perfectlj 

 homogeneous, incompressible, continuous body, in- 

 capable of being resolved into simpler elements 01 

 atoms; it is, in fact, continuous, not molecular. 



' ' Gravitation is explainable by differences of pres- 

 sure in the medium, caused by some action between it 

 and matter not yet understood. Cohesion is explain- 

 able also, probably in the same way. 



" Light consists of undulations or waves in the 

 medium ; while electricity is turning out, quite possi- 

 bly, to be an aspect of a part of the very medium 



itself."! 



" One continuous substance filling all space; which 

 can vibrate as light; which can be sheared into posi- 

 tive and negative electricity; which in whirls consti- 

 tutes matter, and which transmits by continuity, and 

 not by impact, every action and reaction of which 

 matter is capable. This is the modern view of the 

 Ether and its functions. "J 



" The vibrations of light are not such as can be 

 transmitted by a set of disconnected molecules; if by 

 molecules at all, it must be by molecules connected 

 into a solid; i. e., by a body with rigidity. Eigiditj 

 means active resistance to shearing stress, i. e., to 

 alteration in shape ; it is also called elasticity of figure ; 

 it is by the possession of rigidity that a solid differs 

 from a fluid. For a body to transmit vibrations at 

 all, it must possess inertia ; transverse vibrations can 

 only be transmitted by a body with rigidity. All 

 matter possesses inertia, but fluids only possess 

 volume elasticity, and accordingly can only transmit 

 longitudinal vibrations. Light consists of transverse 



* Modern Views of Electricity, by Oliver J. Lodge, p. 339. 

 + Ibid, 338. % Ibid, p. 358. 



