54 Trowbridge — New Emission Theory of Light. 



regarded, as in the case of the canal rays, of a balance between 

 the effect on the atomic motions and the effect on the environ- 

 ment. The difference of phosphorescent effect of cathode and 

 positive* rays is mainly a question of energy and not a differ- 

 ence in kind. 



As I have previously remarked, our experiments on electrons 

 in Geissler tubes are conducted in an environment filled, on my 

 hypothesis, with electrons. The magnetism of the field is also 

 an exhibition of a certain selectivity of path of the electrons 

 of outer space. 



If the sun is constantly throwing forth negative electrons, it 

 is, according to Franklin's hypothesis, being positively charged 

 every instant, and recharged, perhaps from the electrons of 

 outer space. Every flame throws off negative electrons and is 

 constantly being reduced to a positive state. Perhaps in this 

 interchange we can trace the intermittent action, amounting to 

 billows of pulses, of the waves of light. If we examine the 

 tendencies of Physical Science from the time of Sir Isaac 

 Newton, we see a tendency to abandon intangible media and 

 to base all phenomena upon the motion of matter. Indeed, I 

 am tempted to paraphrase Tyndall's much-quoted remark, that 

 we may be led to discern "in matter the promise and potency 

 of all terrestrial life" f by substituting motion and matter for 

 " in matter." It has become a serious question, how the phys- 

 icist, in entertaining a belief in an intangible ether, the whirls 

 of which constitute matter, — a belief that electricity is another 

 intangible something not matter, in an electron which is an 

 essence with an essential tail tied to it by a knot of something 

 thinner than any gas, — can escape being welcomed into the 

 ranks of the metaphysician and philosopher. To escape this 

 suppression of his identity, I believe the physicist must reso- 

 lutely cling to a belief in both motion and matter. 



*It maybe suggested, that the effect of magnetic fields on non-magnetic 

 metals is feebler than that on the positive rays. An atom of gas, however, 

 has a finer suspension than any we can accomplish in the case of a metallic 

 filament. 



f Belfast address. 



