April 26, 19CX)] 



NATURE 



gas. Now the size at which these motions are developed 

 are comparable with the wave-length of the ether dis- 

 turbances of the period of the motion. In the case of 

 irregular disturbances, such as cause temperature phe- 

 nomena in solids and liquids, one cannot define precisely 

 the size of the ether disturbances, because they are of all 

 sorts of sizes, being irregular in the same way as the 

 matter motions are irregular ; but it is known that at 

 each temperature there is a particular wave-length, round 

 which the ether vibrations may be grouped, and that this 

 average wave-length is shorter the higher the tempera- 

 ture. The wave-lengths of these vibrations, so far as 

 they have been observed, vary from 2'4X lo"-^ to ic'cm. 



It is at once evident that the average size of the ether 

 motions is very much greater — quite a thousand times 

 greater— than the size of the molecular motions. In the 

 molecular motions we could not expect to find any 

 irregularity of distribution within distances such as we 

 can see with a microscope, because within a visible 

 volume there will be millions of molecules, and the 

 average motion will be all that we can expect to see. 

 Is it necessarily so as regards the ether motions which 

 exist on so much a greater scale.' Is there any way in 

 which these very much larger scale phenomeiia may be 

 expected to affect matter on a scale comparable with 

 their own size, and which consequently we might expect 

 to be able to see, and which might produce eff"ects on 

 masses of matter consisting of millions of molecules 1 



We may consider in this connection an analogy from 

 sound. In sound we can have small solid objects, such 

 as masses supported by springs, which give out waves 

 in air very much longer than the sounding object. A 

 tuning-fork, for example, may be only a few centimetres 

 long, and may give out waves a metre long. The balance 

 wheel in a watch vibrating quarter seconds would generate 

 waves — feeble ones no doubt, but still waves — 80 metres 

 long, or some 8000 times the linear dimensions of the 

 vibrating object. Similarly the vibrations of molecules 

 generate ether waves many thousands of times as long 

 as the linear dimensions of the molecules. On the other 

 hand, solid bodies may be much longer than the air 

 waves they produce. A bar of steel vibrating longitudin- 

 ally would be fifteen times as long as some of the air 

 waves it would generate. A pipe full of air would be 

 of about the same length as the air waves to which it 

 would resonate, not less than about a quarter as long. 

 If, then, we had a large number of sounding bodies, some 

 small ones like small tuning-forks, balance wheels, and 

 such like, and others like pipes of a size comparable 

 with the air waves, we would expect that when the small 

 ones were all sounding, the larger ones would resonate 

 to their corresponding waves, and thus be set in vibration 

 by the waves originated in the smaller bodies. 



In the case of electromagnetic waves we should expect 

 the same result. If there are bodies comparable in size 

 with the heat waves in the ether which can have electro- 

 magnetic vibrations produced in them of the same 

 periods as those emitted by the molecules, these bodies 

 should resonate to these heat waves. Now, by utilising 

 the ordinary process of conduction in metals, we know 

 that it is possible for electromagnetic vibrations to exist 

 in conductors of a small size, down to a {q\>i millimetres 

 in diameter ; and there is no reason to doubt that by 

 means of conduction very much smaller bodies can have 

 electromagnetic vibrations in them. Dr. Lodge, indeed, 

 has suggested that the structures in the retina are of 

 about the right size to resonate electromagnetically to 

 waves of the frequency of the light waves that affect our 

 eyes. Larger objects would resonate to the electromag- 

 netic vibrations corresponding to the ordinary air tem- 

 peratures. A sphere lo-^ cm. in diameter would, for 

 instance, resonate to waves of about the greatest length 

 that have been measured by Riibens and Nicholls, and a 

 much larger one could have a harmonic of its funda- 



NO. I591, VOL. 61] 



mental tone excited in it by these'waves. In addition to 

 these vibrations in conductors, non-conductors of one 

 specific induction capacity immersed in a medium of 

 a different specific inductive capacity could also have 

 syntonic vibrations excited in them. From all this it 

 seems quite certain that in small particles of matter there 

 must exist, at all temperatures, electromagnetic vibra- 

 tions of a size comparable with the wave-lengths existing 

 in the surrounding ether. 



What sort of effects might we expect to be produced 

 by these electromagnetic vibrations? Is there any 

 prospect of our being able to detect them.? What 

 amount of energy may there be in this form of vibration 

 on each particle t These are questions to which I am 

 afraid I can only give very vague answers. To the first 

 question, as to what effects may be expected to be pro- 

 duced by these vibrations, I can only suggest in the first 

 place an unequal heating of the particle. The parts of 

 the particle which are the electric nodes, where the 

 electric current alternates and where there are no electric 

 charges, these parts should be kept at a slightly higher 

 temperature than the electric loops. If the particle were 

 not perfectly symmetrical, this would lead to an unequal 

 heating of the particle as a whole, and this may be a 

 cause of those so-called Brownian motions of small 

 particles immersed in a liquid which are so very difficult to 

 explain. In the second place, it may lead to a grouping 

 together of molecules into masses of a size depending on 

 the temperature of the liquid, and to a going about of 

 these groups of molecules and a similarity of the vibra- 

 tions of the component molecules which complicates the 

 theory of temperature in a way that may ultimately, as I 

 have before now pointed out, explain to some extent the 

 difficulties at present surrounding this theory. In the 

 third place, this may be connected with the conditions for 

 the breaking down of simple viscous motion and the pro- 

 duction of vortices in a liquid, though I hardly think an 

 explanation on these lines is required ; and, finally, it may 

 be connected with crystalline forces, the structures in the 

 eye, vital actions in small cells and on a small scale, as 

 in the patterns on diatoms, and possibly with the tem- 

 perature at which vital actions ol certain kinds, such, 

 for example, as consciousness, are possible. These are 

 the merest guesses of a wild kind as to the possible results 

 of what seems to be a vera causa for structures and 

 actions in matter of a size comparable with the wave- 

 lengths of light, and must be taken as merely wild 

 guesses. 



As to the second question, of the prospect of detecting 

 these electromagnetic vibrations in particles of matter, 

 its answer depends so entirely upon the first that I can 

 only leave it to the investigators of the future to try and 

 detect them. That such electromagnetic vibrations exist, 

 I think, can hardly admit of doubt, any more than that 

 the strings of a piano are kept in vibration when loud 

 and irregular noises are produced in its neighbourhood. 



As to the energy of the vibrations upon each particle, 

 I cannot give any satisfactory answer. If the particle 

 were in a region through which a series of plane waves 

 of a constant type were being transmitted, it would no 

 doubt be possible to solve the problem of determining 

 the amplitude of its vibrations in particular cases of 

 assumed shapes of particles. In the actual case of 

 irregular disturbances I do not see, at present, any direct 

 way of attacking the problem. It would apparently 

 require to be attacked statistically, but I doubt whether 

 this would lead to a true result, because there seems some 

 reason to think that trains of uniform waves of con- 

 siderable length do exist in the ether, and if there is any 

 regularity of this kind in the ether motions, a purely sta- 

 tistical treatment, in which the vibrations were assumed 

 to be quite irregular, would fail to lead to a true result. 

 If the energy of these electromagnetic vibrations of its 

 fundamental period on a particle is no greater than 



