THE ACTIVE FORCES OF LIVING ORGANISMS ii 



degree of intensity, and one might speak of those 

 which react with greater vigour as being of higher 

 electrical potential than those whose reaction on the 

 ether was weaker, or was attractive rather than re- 

 pulsive. When a current of electricity is passed 

 through certain substances so as to set up chemical 

 action, it is evident that the attractive or repulsive 

 properties of the atoms so affected are brought into 

 play. Similarly, when the molecules of any sub- 

 stance, such as sealing-wax, are excited by rubbing, it 

 possesses attractive or repulsive power, according to 

 the stuff or substance with which it is rubbed and 

 with which it is brought into relation. The pheno- 

 menon of gravity tends to show that the attractive 

 power of matter may be communicated to the ether, 

 and through the ether to other bodies. Matter in 

 that case is in its normal or quiescent state, and it 

 seems natural to suppose that when it is excited, as it 

 is by rubbing, its effect upon the ether would be far 

 greater. If, therefore, two substances be rubbed 

 together, we might suppose that each would com- 

 municate to the ether permeating the other something 

 of the character of its atoms or molecules. Some- 

 thing of this kind seems to occur when a pith-ball is 

 touched by excited glass or excited sealing-wax. The 

 ether permeating and surrounding the ball may be 

 then supposed to act as a medium of attraction or 

 repulsion, according as the sum of the atomic and 

 molecular influences brought to bear on it agrees or 

 disagrees with the sum of the influences proceeding 



