Supplement to '' Natu7'e,'' August 4, 1923 



187 



effects are connected with atomic bombardment ; 

 so in that respect they differ from the effects just 

 mentioned. 



I would Hken the Richardson effect in some respects 

 more to the Lebedew and Nicholls and Hull detection 

 of the pressure of light, as suggesting an etherial 

 reaction on ordinary matter. 



Referring to this light-pressure ; it is so small 

 that Crookes failed to detect it, just as Faraday failed 

 to detect the Zeeman effect with the appliances of 

 his day and without a Rowland grating ; but the most 

 trivial fact, so it be a fact, is of enormous and may be 

 of cosmic importance. Poynting invoked light-pressure 

 to account for cometary and other astronomical 

 results ; and now Eddington calls upon it to sustain 

 the Atlas-like burden of holding up the billions of 

 tons of superincumbent material which constitutes the 

 crust or envelope of a giant star. An amazing applica- 

 tion of the (terrestrially) almost infinitely small. 



Parenthetically, in using the term so-and-so's 

 " effect," I do so under protest. This personal kind 

 of nomenclature should be temporary, and not outlive 

 the generation of discovery. This kind of naming 

 began with either the Doppler or the Peltier effect, 

 and was right enough when novel effects were few ; 

 but now that they constitute a multitude, we older 

 folk are apt to get confused among the plentiful crop 

 which the more fortunate youngsters are continually 

 evolving. Prof. Richardson is entirely free from 

 blame, for he calls his discovery a gyro-magnetic 

 effect ; which is explicit and satisfactory. 



The Positive Electron, 



Before leaving this part of the subject I should 

 like just to direct attention to what I have written 

 in Nature for November 25, 1922, p. 696, that 

 we have not yet securely discovered the positive 

 electron. The proton has to serve that function for 

 the present, but what the constitution of the simplest 

 known nucleus of an atom is, remains to be determined. 

 Something is known about the proximate or apparent 

 constituents of some heavier atomic nuclei, though 

 not much, but nothing at all of the constituents of 

 the nucleus of a hydrogen atom. It may be an 

 indivisible particle so small and concentrated as to 

 have a mass 1800 times that of a negative electron ; 

 but to me it seems unlikely that this is the right solution. 

 It may, on the other hand, be built up of a stable 

 grouping of hypothetical electrons both positive and 

 negative, — each one being like a mirror image of the 

 other. If so, it remains to be explained why the 

 outstanding charge of all atomic nuclei is apparently 

 positive, and whether that is accurately true. All 

 I advocate is to keep the door open for further investiga- 

 tion, and to persevere with the quest of the positive 

 electron by any methods that may suggest themselves. 



Why negative electricity should differ from positive 

 so greatly, or in any respect save in sign, is not at all 

 clear ; and it is difficult to understand how one of 

 these entities can have been constructed out of the 

 ether, without the simultaneous production of its 

 opposite partner. 



Electrical Theory of Matter. 

 The mechanics of the ether are not yet known ; 

 and until we have devised some system of mechanics 



which applies, not in a blindfold, but in a clear and 

 lucid, manner to the behaviour of the ether, we must 

 remain to some extent in the dark. Here, then, is 

 scope for experiment. At present we are using ether 

 waves to examine the properties of matter, the structure 

 of crystals, the structure of molecules, and even the 

 structure of the atom. But we must go on in due 

 time to use these phenomena for an investigation of 

 the ether itself. We know that movement of matter 

 does not affect the refractive index nor the polarising 

 properties of that matter. But we know that if 

 matter is moving fast enough, it tends to carry some 

 ether with it, and thereby adds to its own inertia to 

 a known and predicted extent. We also know that 

 inertia itself is a magnetic and therefore etherial 

 phenomenon. The way in which J. J. Thomson, 

 Heaviside, and Larmor have worked out the electrical 

 relations between ether and matter, as regards inertia, 

 changes of inertia with speed, and radiation consequent 

 on acceleration, has been a marvellous achievement 

 of our time, of which quite inadequate popular notice 

 has been taken. Still there it is. They have laid the 

 foundation of the Electrical Theory of Matter, and 

 have opened up a way for our descendants to explain 

 nearly all the properties of matter in terms of the 

 ether, and possibly the very existence of matter itself. 



We do not yet know how an electron is composed. 

 We know still less — if that is possible — how a proton 

 is composed. But that they ultimately will turn out 

 to be etherial structures of some kind is possible and, 

 as I think, probable. 



Meanwhile we know that not only the mass of 

 bodies, but their shape, is affected by motion through 

 the ether ; this was demonstrated by that great experi- 

 ment of Michelson's, which I regard primarily as an 

 experiment on matter by means of light, and not an 

 experiment on light by means of matter. It may 

 hereafter be regarded by a sensible though preposterous 

 historian — that is, one who puts the cart before the 

 horse — as the first and only verification of the Fitz- 

 Gerald-Lorentz theory of modified electrical cohesion, 

 or peculiar interaction between moving particles. It 

 has been used as the foundation of the Theory of 

 Relativity. But that is an ingenious offshoot or 

 excrescence. I should like everybody to realise that 

 the Electrical Theory of Matter had already accounted 

 for nearly all the things which drop out so naturally 

 from the theory of relativity : such as the increase 

 in mass, the FitzGerald contraction as a reality, the 

 Fizeau effect on light ; even an extra revolution of 

 the axes of a planetary orbit, unless gravitation itself 

 is modified by motion. (See several Articles in the 

 Phil. Mag. between August 1917 and June 1918, by 

 Prof. Eddington, G. W. Walker, and myself ; beginning 

 with page 81 of vol. 34, and with conclusions sum- 

 marised on pp. 143, 482, and 486 of vol. 35.) The 

 Electrical Theory of Matter may conceivably be made 

 to account for the two other as yet incompletely 

 verified gravitational effects so brilliantly predicted 

 by Einstein. But that remains to be seen. 



Possible Experiments. 



Eimits of space will not permit me to deal here with 

 tli(> ])(>ssibility of an experiment to determine whether 

 there really is etherial circulation along magnetic 



