1 1 1: 1 J rz's 1 : x vvau m !•: nts.* 



'•oil! yes; [ uiuleistaiul it all uow. Electricity is tlie a'tlier;" or, 

 "Yes; it's Just like everytliiiii;- else: electricity is a vibration." These 

 are the remarks one hears made by those who think that a few scat- 

 tered words picked up at a. popular lecture make thiugs (piite clear. 

 It is no doubt unfortunate that repeating- a form of words is a different 

 nr.itter iVom understanding them, and still more different from under- 

 standing the subject they are intended to explain. In this case there 

 is the added misfoituue that the fmiu of words is not accurately 

 repeated, and in its inaccurate form d(»es not mean what is true. It is 

 often hardly vorth while remarking this to those Avho make these state- 

 ments, because the words convey to them little or uo signitication, and 

 are to them as true as any other unmeaning sentence. Tlie connection 

 between electricity and tlie aether is certainly not, as fai* as is known, 

 well described by saying that " electricity is the aether," and we can not 

 say with any certainty that electricity is or is not a vibration. Hertz's 

 exi)eriments have given an experimental proof of MaxweH's theory that 

 electrica.l phenomena are due to tlie a-ther, ami llerzt's exi)eriments 

 deal with vibiations. One can not however say, because the pressure 

 of 15 pounds ]»er square inch exerted by the atmospheie is due to the 

 air, that therefore "pressure is the air"; nor even, because a person 

 who studied the projx'rties of the air had studied them by means of 

 sounds propagated through it, can one assert that '' pressure is a vibra- 

 tion." It is to be hoiked lu) one will now assert that •' electricity is 

 pressure." The example is gi\en to illustrate the absurdity of the state- 

 ments nnide as deductions from re(;ent experiments, and not to teach 

 any new theory. And yet one comes across [)eoi)le who, after listening 

 to an interesting lecture Lord IJayleigh might give, illustrated by Mr. 

 Boys's sound-pressure meter, would make the above statements, and 

 really think they understood them. 



The subject is very diflllcult; one that has engaged the attention of 

 thoughtful and clever men for many years, and is still in many ])arts, 

 even to the most acute, shrouded with dilliculties, uncertainties, and 

 things unknown, so that nobody need be the least ashamed of not fol- 



* From .Va/«re, April 9, 1891; vol. xi.m, pp. 536-538; aud May 7 .ind 11, 1891; vol. 

 XLiv, pp. 12-14, aud 31-35. 



203 



