i8o 



KNOWLEDGE & SCIENTIFIC NEWS. 



[August, 1904. 



for the present, unanswerable. Electricity is, on the 

 theory we are attempting to sketch, positi\e or nega- 

 tive according to the direction of the originating strain. 

 .•\ positive electron might be imagined to resemble a 

 spiral nebula of the right-handed sort, a negative one a 

 left-handed spiral, or vice versa. The analogy is, per- 

 haps, fanciful ; yet it helps towards obtaining a mental 

 picture of objects which, insignilicant and elusive 

 though they appear, may be the initials and ultimates of 

 this strange world. 



The forces, at any rate, by which it is at present kept 

 going are evoked ad libitum by the pioneers of modern 

 research from the ethereal plenum. The actualities of 

 matter are potentialities in the ether. " All mass," in 

 Professor J. J. Thomson's opinion, " is mass of the 

 ether, all momentum, momentum of the ether, and all 

 kinetic energy, kinetic energy of the ether.* Only if 

 this be so, he adds, " the density of the ether must be 

 immensely greater than that of any known substance." 

 The condition is startling, but in dealing with such sub- 

 jects, we must not be too curious about anomalies. 

 They come, as the ghosts appeared to Odysseus in 

 Hades, at first one by one, then in an awe-inspiring 

 swarm. Yet, in spite of the perplexities they occasion, 

 we can discern with growing sureness of insight the 

 amazing reality of the universal medium. It is, in a 

 manner, the only reality. For what is manifest to sense 

 is subject to change. We can conceive that the visible 

 frame-work of material existence might crumble and 

 dissolve, like "the baseless fabric of a vision," into 

 seeming nothingness. But a substance that is inap- 

 prehensible is, to our limited ideas, imperishable. The 

 ether is, indeed, the seat of intense activities, wnich lie 

 at the root, most likely, of all the processes in Nature. 

 An absolutely uniform medium, however, can scarcely 

 be imagined to energise or react. Some kind of hetero- 

 geneity it must possess; and the heterogeneity, pro- 

 duced, in Dr. Larmor's view, by strains, is associated 

 in Professor Reynolds's theory, with structure. 



The " Sub-Mechanics of the Universe " are here 

 made to depend upon the fitting together of ineffably 

 small, ideally rigid grains. A misfit gives rise to 

 matter, which might hence be defined as " ether out of 

 gear "; and the misfit can be propagated endlessly from 

 one range of granules to the ne:;t. This propag.ition 

 through the ether of an abnormal arrangement of its 

 constituent particles, without any transference of the 

 particles themselves, explains the phenomena of matter 

 in motion. A concrete existence belongs to the ether 

 alone. It is composed of round, aboriginal atoms, the 

 diameters of which measure the seven hundred thousand 

 millionth part of the wave-length of violet light, t 

 They are packed closely together, yet not so closely but 

 that free paths are left to them averaging in length the 

 four hundred thousand millionth part of their diameters. 

 This inconceivably small relative motion sulfices, never- 

 theless, to render the medium elastic; is, indeed, " the 

 only cause of elasticity in the universe, and hence is 

 the prime cause of the elasticity of matter." The 

 medium so formed is ten thousand times denser than 

 water; it exerts a mean pressure of 750,000 tons on the 

 square inch; the coefficient of its transverse elasticity is 

 9 X 10-1 (in C.G.S. units); which gives a velocity of 

 transmission identical with that of light for vibrations 

 of the same type, while longitudinal waves are propa- 

 gated 2.4 times more rapidly. The scheme further in- 

 cludes a plausible rationale of gravity and of electrical 

 effects; so that there is much to warrant the claim of 

 its author to have excogitated " the one and only con- 

 ceivable purely mechanical system capable of account- 



ing for all the physical evidence, as we know it, in the 

 universe. " 



The machine, to be sure, lacks motive power; but 

 that is a want which no human ingenuity can supply. 

 Its source is obscured in the primal mystery of creation. 

 And, as regards the preliminary assumptions required 

 for the constitution of an atomic ether, inclined though 

 we might be to cavil at them, we should, perhaps, act 

 more wisely in following Dr. Larmor's advice by ab- 

 staining from attempts to explain " the simple group of 

 relations which have been found to define the activity 

 of the ether. We should rather rest satisfied," he 

 tells us, " with having attained to their exact dynami- 

 cal correlation, just as geometry explores or correlates, 

 without explaining, the descriptive and metric pro- 

 perties of space.' ; Yet one cannot help remarking 

 that the properties of space are not ordinarily modified 

 to suit demonstration, while those of the ethereal 

 medium are varied at the arbitrary discretion of rival 

 cosmogonists. In the future, when they come to be 

 more clearly ascertained, they will, perhaps, form the 

 basis of a genuine new science. Already, the study of 

 ethereal physics excites profound interest and atten- 

 tion. Nor is it possible to ignore the gathering indica- 

 tions that it will impose qualifications upon principles 

 consecrated by authority and hitherto regarded as 

 fundamental. The grand modern tenet of the con- 

 servation of energy, for example, may need a gloss; it 

 may prove to be admissible only with certain re- 

 strictions. The second bulwark of the scientific edifice 

 is even more seriously undermined. For the " strain- 

 theory " of atomic constitution necessarily includes the 

 conception of opposite distortions corresponding to 

 positive and negative electricity. And the further in- 

 ference lies close at hand that these, by combining, 

 may neutralise one another. The coalescence, then, of a 

 positive and negative electron should result in the 

 smoothing out ol the complementary strains they stand 

 for; and there would ensue the annihilation of a pair of 

 the supposed ultimates of matter. The event might be 

 called the statical equivalent of the destruction of light 

 through interference. That its possibility should be 

 contemplated even by the most adventurous thinkers is 

 a circumstance highly significant of the subversive 

 tendencies inherent in recent research. Already, in 

 May, 1902, Professor J. A. Fleming^ pointed out that 

 " if the electron is a strain-centre in the ether, then 

 corresponding to every negative electron there must be 

 a positi\e one. In other words, electrons must exist 

 in pairs of such kind that their simultaneous presence 

 at one pt)int would result in the annihilation of both of 

 them." The consequence thus viewed in the abstract 

 finds concrete realisation, if Mr. Jeans's suggestion be 

 adopted,!! in th;.- processes of radio-acti\ity, which may 

 consist " in an increase of material energy at the ex- 

 pense of the destruction of a certain amount of 

 matter." "There would, therefore, be conservation 

 neither of mass nor of material energy." 



No longer ago than at the opening of the present 

 century, such notions would have been scouted as 

 extravagant and paradoxical; now there is no escape 

 from giving them grave and respectful consideration. 

 Scientific reason has ceased to be outraged by hypo- 

 theses regarding the disappearance of mass and the 



* Etcctytcitf an I Multcr, p. 51. 



t The Stiuiturc of llic Viiiveisc, Kedu Loctur 



I Natnic. June, Vol. I, XII, |i. 451. 



§ Pi'Oiiiiliiigs Royiil Inititutinn, Vol, W'll, jj 



II Nalure, Vol. LXX, p. 101. 



e, June 10, 1902, p 14. 



