250 ROCHESTER ACADEMY OF SCIENCE. [Feb. 26, 



respondence whatever between the behavior of such storms and the 

 manner in which radiations of heat and light are originated and propa- 

 gated from sun to earth. 



Recently it has been discovered by Hertz that there are ether 

 waves which do not produce light or heat or any other manifestation 

 of radiant energy but still are capable of having electrical effects. 

 These electric waves can be reflected the same as light waves and 

 exhibit the remarkable peculiarity of passing through substances such 

 as wood, which are impervious to light. Still they are wave motions 

 only and are subject to the limitations which have been indicated 

 throughout the course of the discussion. Their behavior resembles 

 that of sound waves so closely that the term electrical resonance has 

 been employed to designate their modes of action, which involve inter- 

 ference phenomena similar to those attended by increase or diminu- 

 tion of effect in acoustics. They are simply waves of a particular 

 length and consequently have their own characteristic effects just as 

 others of different lengths have chemical, or heating, or luminous 

 effects chietly. Mere differences of wave length does not alter the 

 principles of radiation. 



Nor will it help matters to conceive of vortices or rotary move- 

 ments of the ether having complicated systems of interferences. It 

 is possible that something of the sort may exist in magnetic fields 

 that are sufficiently strong but the effects thus produced in immediate 

 proximity to the poles of a magnet have nothing whatever to do with 

 radiation in the ordinary sense of that term. Thus the rotary mag- 

 netic field ot Tesla and phenomena of kindred character do not enter 

 into the question under discussion. 



Not only is proof lacking that electrical energy is transferred by 

 radiation from one locality to another, but there is positive proof on 

 the other hand that it is thus conveyed with the utmost facility by the 

 process known as conduction. Such conveyance by the agency of 

 material substances having the requisite physical properties is con- 

 sistent with the view that electricity is essentially a property of matter 

 and not of the ether of space which was discussed at the outset. Elec- 

 trical action of every species is to be classed with such properties of 

 atoms as cohesiveness, chemical aftinity, weight and the like, all of 

 which are concerned in procuring definite forms of aggregation of 

 matter. Thus in the case of particles free to move there are 

 electro-magnetic systems of arrangement which have been fully 

 identified and whose prominent characteristics are well known. 



