Toate ties 
74 Mr Zeleny, On the Conditions 
7. An alcohol surface, both in air and in carbonic acid, was) 
found to behave in the same way as a water surface does in| 
carbonic acid, both as regards the oscillations with an intermittent 
current, and as regards the subsequent conical form of meniscus, | 
For voltages well above that for which the steady conical surface 
changed into a blurred agitated one, the appearance became that! 
shown at “c,” Fig. 2, where there are a number of fine points with) 
their attendant dark streaks arranged along the circumference of! 
a raised edge. . 
For voltages at which the oscillations of the meniscus first) 
appeared, these oscillations had a much smaller amplitude with | 
alcohol than they did with water, and the quantity of electricity | 
reaching the plate at each movement of the meniscus was also, 
much less in the case of alcohol. : 
The behaviour with alcohol remained quite unchanged as the| 
pressure was reduced below that of the atmosphere, in both air| 
and carbonic acid. The cone form of meniscus was observed in| 
air at a pressure of 12 cms, of mercury and in carbonic acid at a 
pressure of 25 cms. of mercury, these being the lowest pressures | 
used with these gases. Moreover the potentials at which the! 
current ceases were found to be the same in both gases and for | 
all of the pressures used. This potential was, however, only about | 
six-tenths of that at which the discharge stopped in air. 
Cc 
(0) 
2) b e if 
8. When the cone-shaped discharge surface of alcohol was ’ 
examined with a microscope magnifying about 50 diameters in | 
the instantaneous light of a Leyden jar spark, the dark streak | 
seen along the prolonged axis of the cone was not resolved into | 
drops. When examined without a microscope in weak continuous | 
light, a form of brush of considerable angle was faintly seen ex- 
tending outward from the end of the cone; but this brush showed | 
no luminosity when examined in the dark. A luminous brush of 
the same form as this one was previously observed (§ 2) at the end 
of a hemispherical drop of water at each of the intermittent dis- | 
charges from it. ; 
ea 
A 
d 
Fig. 3. 
C 
