EFFECTS OF ELECTRICAL WAVES 4938 
pass between the electrodes, as it does in my experiments, 
but we have to do with a silent discharge. In this way, 
however, the oscillatory character of the discharge practi- 
cally disappears. As is well known, a tuning-fork emits a 
sound only when the prongs, after they have been moved 
from their state of rest, spring back quickly. When they 
return to a state of rest very slowly, they do not give rise to 
sound. It is the same in the case of a discharge. In the 
case of a spark discharge we deal with an abrupt release of 
the tension which must occur in an oscillatory way. In the 
case of a silent discharge we do not deal with oscillations at 
all. If Danilewsky speaks of an oscillatory discharge 
under such circumstances, it is to be remembered that 
in reality the oscillatory character of the discharge dis- 
appears so completely in his experiments, that they cor- 
roborate beautifully my view that these effects are not 
determined through oscillations, but through a single elec- 
trostatic discharge. 
Of course, it might yet be maintained that electric waves 
are present in this case in so far as the interruptions by the 
hammer of the Ruhmkorff are periodic. If we estimate these 
interruptions in the Ruhmkorff coil as 60 per second (which 
is certainly high), then, when the velocity of light is in 
round figures 300,000 km., the wave-length is over 5,000 
km.! Does Danilewsky expect us to believe that these 
waves can interfere between his electrodes which are sepa- 
rated from 50 to100cm.? It is also entirely wrong to apply 
to such waves the term ‘‘rays.” We expect rays to move in 
a straight line, and for this reason we do not speak of sound- 
rays, since these can go around acorner. The ‘‘rays”’ of 
Danilewsky would not only go around a corner, but around 
the Alps, or around the moon. In a similar way there is no 
sense in saying, as Danilewsky does, that in these experi- 
ments a “neutralisation des polarités électriques” occurs. 
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