the Discharge of a Leyden Jar. 375 
As their results, nevertheless, would have no particular applica- 
tion to the matter in hand, I made a new set of experiments 
with the same apparatus, using also the ‘same electrodes and 
battery. 
Duration of the aureol with brass balls as electrodes. 
Striking distance. Duration. 
1 millimeter. "026 sec. 
2 “ce ‘Ol 5 “ce 
3 sc “0 l 2 oo 
4 “ “009 it 
5 “ ‘006 is 
Ata striking distance of ten millimeters the aureol was not 
visible. The light of the aureol corresponding to one of the 
electrodes was violet, that due to the other had a hue approach- 
Ing red. ith small striking distances the two streaks were 
i contact, but separated as the distance between the electrodes 
was increased. 
Duration of the aureol with platinum points as electrodes, the 
length of the simple induction spark being 48°7 millimeters. 
Striking distance. Duration. 
1 millimeter. ‘022 sec. 
2 “ “020 ce : 
3 cc 0 ] 8 é 
10 oe alee ae ee 
With ten millimeters only one of the streaks was visible; as 
before, they were red and violet. 
In both of these experiments the duration of the aureol 
a8 great an interval as 026 sec., which is the maximum dura- 
tion of the multiple discharges described in this paper. 
-he general result obtained in these experiments may then 
be summed up as follows: if a Leyden jar, of a selected size, 
it is evident that we may regard two 
vening layer of air a millimeter thick, as a minute Leyden jar, 
Tepresenting the last of the series. 
