THE PATH OF EVOLUTION 



883 million million in a second, and the fastest known 

 sound vibrations being, say, 40,000 in a second, light vi- 

 brations are 22,075 millions to one sound wave. These 

 relations are given merely to show how almost in- 

 finitely minute and rapid the undulations of the ether 

 are compared to those of the atmosphere. How almost 

 inconceivably smaller than those of air must be the 

 ultimate particles of the ether if it is composed of 

 discrete particles as all other forms of matter are. 

 How easily, therefore, they might interpenetrate all 

 other matter, even though the constituent atoms of 

 the air and of fluids are so minute themselves as to 

 escape all tangible or occular demonstration. 



Maxwell says with regard to the theory of a semi- 

 solid or continuous constitution of the ether : " The 

 theory opposed to the atomic structure of the ether 

 and of matter, generally known as that of Anaxagoras, 

 in which bodies that appear to be homogeneous and 

 continuous are so in reality, as Xenophanes taught, 

 is incapable of demonstration. To explain the proper- 

 ties of any substance by this theory is impossible. 

 The properties of such substances if existing could 

 only be admitted as ultimate facts." There is no 

 explanation, for it cannot be explained. 



The Vortex theory, suggested by Von Helmholtz, 

 and elaborated by Sir William Thompson (now Lord 

 Kelvin) over thirty years ago, as applicable to the 



128 



