THE ACTIVE FORCES OF LIVING ORGANISMS 13 



light are transmitted, for it has been argued that an 

 absolutely indivisible medium cannot be thrown into 

 waves. The weakness of this argument seems to lie 

 to some extent in the fact that use is made of words 

 generally employed to represent finite ideas to describe 

 that which is essentially infinite. In the first place, 

 it is evident that the ether is divisible by the mole- 

 cules and atoms which move and have their being in 

 it ; but, on the other hand, it will be seen that a 

 medium, consisting of matter in a state of infinite 

 division, must of necessity be in a certain sense indi- 

 visible. It is a case of les extremes se touchent. The 

 air around us may in a more limited manner be said 

 to be at one and the same time both infinitely divided 

 and indivisible. We shall probably obtain a more 

 correct idea of the ether if we attribute to it in a still 

 higher degree many of the properties of air with which 

 we are familiar. Amongst these we may mention two 

 which are of importance, the first being the property 

 of being thrown into waves, and the second that of 

 conducting impressions from one substance or collec- 

 tion of molecules to another. That the ether possesses 

 this latter property in a very high degree we may 

 believe; for the more matter is divided, the less do 

 the particles of which it is composed possess any 

 individuality, and the more readily do they obey any 

 impulse they may receive. 



There is a second property of the ether which may Tension of 

 be said to be evolved out of its all-pervading nature a iLtmfl 

 and its conductivity, and this is tension. conduc-" 



tion. 



