If the energy of the electrons is sufficient, these electrons will in
fact rush forth and be propagated in the air or in the insulating
medium interposed; but the phenomena of the discharge will in general
be very complex. We shall here only examine a particularly simple
case, viz., that of the cathode rays; and without entering into
details, we shall only note the results relating to these rays which
furnish valuable arguments in favour of the electronic hypothesis and
supply solid materials for the construction of new theories of
electricity and matter.
For a long time it was noticed that the phenomena in a Geissler tube
changed their aspect considerably, when the gas pressure became very
weak, without, however, a complete vacuum being formed. From the
cathode there is shot forth normally and in a straight line a flood
within the tube, dark but capable of impressing a photographic plate,
of developing the fluorescence of various substances (particularly the
glass walls of the tube), and of producing calorific and mechanical
effects.
Pages:
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337