CH. XXL] VIEWS OF ATOMS 201 



nebula may be due to shocks and collisions somewhat 

 like the X-radiation from some atoms. 



The disproportion between the size of an atom and 

 the size of an electron is vastly greater than that 

 between the sun and the earth. If an electron is 

 depicted as a speck one-hundredth of an inch in 

 diameter, like one of the full-stops on this page for 

 instance, the space available for the few hundred or 

 thousand of such constituent dots, to disport them- 

 selves inside an atom, is comparable to a hundred-feet 

 cube ; in other words, an atom on the same scale 

 would be represented by a church 160 feet long, 80 

 feet broad, and 40 feet high, in which therefore the 

 dots would be almost lost. And yet on the electric 

 theory of matter they are all of the atom that there 

 is ; they " occupy " its volume in the sense of keeping 

 other things out, as soldiers occupy a country ; they 

 are energetic and forceful though not bulky ; and in 

 their mutual relations they constitute what we call 

 the atom of matter; they give it its inertia; they 

 enable it to cling on to others which come within 

 short range, with the force we call cohesion ; and by 

 excess or defect of one or more constituents they 

 exhibit chemical properties and attach themselves 

 with vigour to others in like or rather opposite case. 



That such a hypothetical atom, composed only 

 of sparse dots, can move through the ether without 

 resistance is not surprising. They have links of 

 attachment with each other, but, so long as the 

 speed is steady, they have no links of attachment 

 with the ether ; if they disturb it at all, in 

 steady motion, it is probably only by the simplest 

 irrotational class of disturbance which permits of 

 no detection by any optical means.* Nor do 



See Lodge, Phil Trans. 1893, vol. 184, pp. 750-754; also vol. 189, p. 166. 



