November 16, 1900.] 



SCIENCE. 



743 



it carries will account for its full quantity 

 of inertia. 



So long as we knew nothing of the size of 

 the corpuscle, and since there might be a 

 thousand corpuscles in a hydrogen atom, and 

 yet each corpuscle be about 3.10 ~' cms. in 

 diameter, we were hardly justified in hold- 

 ing that inertia is an electric phenomenon. 

 But when we take into consideration, in ad- 

 dition, the writer's proof that the diameter 

 of the corpuscle must be less than j-^-^ the 

 diameter of the atom, and that this is the 

 superior limit in size, we have a reasonable 

 basis for holding, as the writer has done,* 

 that the corpuscular charges are the cause 

 of the inertia of matter. 



Assuming this, we arrive at the result 

 that the corpuscle is about f x 10 ~" cms. 

 in diameter. The ionic equivalent being 

 about 4 (± 1) X 10 ~" e. s. units, we find 

 for the electrostatic tension and pressure at 

 the surface of the corpuscle, about 2.10'^ 

 dynes. 



One of the theorems immediately dedu- 

 cible by Qualitative Mathematics is that, 

 " Whenever the electric or magnetic forces 

 act in the presence of matter, the resultant 

 effect is made up of two terms, one express- 

 ing the result of the action on the matter, 

 the other that of the action on the ether." 



We have seen that the electric stresses 

 produce a change of volume in matter, and 

 hence we must have also an efiect of the 

 same quality in the ether. Such a change 

 of density in the ether would produce a 

 gravitational attraction, and we may now 

 calculate what value the ether constants 

 must have in order to produce the observed 

 amount of gravity which is associated with 

 the corpuscle. 



Taking Boys's value for the gravitational 

 attraction of two masses, each of one 

 gramme, and one cm. apart, i. e., 6.65 x 

 10 ~^, we get for the gravitational energy of 

 the corpuscle about 10 ~^® ergs. 



* Elect. World, May, 1900. 



From this and the electrostatic stress we 

 can calculate the volume elasticity, and we 

 find it to be about 10". 



But I have previously shown that the 

 density of the ether is about 0.66 and its 

 rigidity about 6.10"'. 



Hence we can calculate the value of the 

 compressional or gravitational wave, and 

 find it to be approximately 5.10"° cms. per 

 second. 



It will be at once seen that this value 

 agrees with our astronomical facts, and that 

 it does away with a great many optical dif- 

 ficulties. For in the first place it makes 

 the compressional wave vanish, and in ad- 

 dition, which is of the greatest importance, 

 it makes the amount of energy in the com- 

 pressional wave infinitesimally small.* 



We may summarize our conclusions as 

 follows : 



The ether itself is a composite body, hav- 

 ing a structure whose elastic properties are 

 analogous to rubber. This is shown by the 

 low value of the rigidity as compared with 

 the compressibility, and by the form of the 

 equation expressing the relation between 

 ff and p.. 



This would immediately suggest a vortex 

 theory, even if the quality of the ionic 

 charge, i. e., 3I/T, were not called to the 

 attention. If we take Fitzgerald's vortex 

 theory, and develop it along the lines indi- 

 cated by my theory we have the vortices 

 analogous to what, in the case of India rub- 

 ber, I have called the ' skein material,' and 

 the fluid in which the vortices form, which, 



* In a paper on Comet's Tails, Asirophysical Review, 

 January, 1897, the writer showed that all the phe- 

 nomena so far noted in this connection, including the 

 bridge of Biela's comet, the apparent retardation, 

 the shape, etc., could be accounted for by supposing 

 that the ultra-violet light of the sun acted on the sur- 

 face of the nucleus of the comet to throw off negatively 

 charged particles. It is possible that this compressive 

 wave may be a factor in this discharge, though on 

 the other hand it is possible that the light itself may 

 be sufficiently efiective. 



