56 ON MATTER, FORCE, AND MOTION IN SPACE. 



applicable to the whole theory of undulations to have 

 attained conclusions which no common reasoning or 

 experiment could reach methods which render the 

 very multiplicity of the actions involved an exponent 

 of their congruity and constancy. There is a certain 

 analogy here to those researches of Lagrange and La- 

 place, which submit even the secular perturbations of 

 the planetary system to a principle of mutual compen- 

 sation, acting through vast periods of time, but ever 

 tending to maintain the order and permanence of the 

 whole. It is by researches and results such as these 

 that man may be said to be raised above his humanity. 

 But the ether of space must be looked to for other 

 functions beyond the transmission of light, and its ad- 

 juncts of calorific and actinic or chemical rays. Science 

 taxes it still further as the possible, though improved, 

 medium for transmitting the forces of gravitation and 

 magnetism through space. We can only conceive the 

 propagation of these forces by intervention of matter. 

 Newton held this explicitly as to gravitation. Every- 

 thing we know of the magnetic or electric element 

 connects this also with matter, and by far more com- 

 plex relations of evolution, conduction, induction, and 

 chemical action. Gravitation, to our present know- 

 ledge, stands alone among the great forces of nature. 

 If it be ever brought into correlation with other powers, 

 I am inclined to believe that the magnetic element will 

 be the first to come into this conjunction, with the 

 possible intervention of ether as a part of such correla- 

 tion. I incline the more to this speculation from its 

 concurrence with a persuasion I have long held, that if 



