on Electric Discharges through Water. 151 
The following experiments were made with the apparatus 
described p. 14,6, and shown by fig. 8, 9, and 10. 
Experiment 1. At o h 40' P. M. began to produce discharges 
with a double plate twenty-four inch machine, in water taken 
from the cistern: and at i2 h 6' P. M. of the same day there had 
been written down 10200 discharges, each of which occasioned 
air to ascend from the bottom of the wire and brass cup. The 
quantity of air obtained was now apparently about one-fourth 
of a cubical inch, and it occupied nearly half of the tube ; the 
water in which was by this time very muddy. 
After standing till the day following at noon, when the pro- 
cess was again commenced, it did not appear that any of the 
gaz had been absorbed by the water over which it stood. 
At 2 h 35' P. M. began to produce discharges, and at 8 h P. M. 
had passed 6636 ; which, together with those of the preceding 
day, amounted to 16836. The tube was now ± full of gaz, and 
there seemed to be almost half a cubical inch ; for it was ob- 
served, that the gaz was this day yielded at double the rate it 
had been the day before. This was accounted for from the 
diminished pressure upon the electric fire, by the tube contain- 
ing gaz instead of water. 
At this time, namely, at 8 h P. M. I was surprised, on the 
passing of a discharge, by a vivid illumination of the whole 
tube, and a violent commotion within it; with, at the same 
time, the rushing up of water, instantly to occupy rather more 
than f of the space which had been occupied by gaz. 
The residue of gaz was not diminished further by an electric 
spark ; and to the test of nitrous gaz it appeared to be rather 
worse than atmospherical air, as it consisted of rather less than 
one part of oxygen, and three parts of nitrogen or azotic gaz. 
