ELECTRIC DISCHARGE WITH THE CHLORIDE OF SILVER BATTERY. 227 
intermittent extra currents would in all probability occur wben the potential of the 
condenser bad risen only a very little above that of the terminals in the tube, and 
would consequently take place very many times more rapidly than 5 2 ‘7 7 times in a 
second of time, as nothing approaching the full charge of the condenser passes on 
these occasions. 
The phenomena do not occur when a very large condenser, 42 '8 microfarad for 
example, is employed in the way shown in fig. 26, Part I., page 100, for then no 
current passes through the tube until the condenser has become charged to a 
sufficiently high potential, and this occupies a sensible time, about thirty seconds, and 
when it passes it does so continuously and steadily. 
On the other hand with a small condenser, used as shown in fig. 66, the current 
commences to pass almost instantaneously through the tube, and in all probability 
divides itself as soon as the key K is pressed down, part continuing to pass through the 
tube, and part entering the condenser and discharging itself intermittently through 
the tube. 
In order to test whether it would be possible to render evident pulsations, in the 
current, too feeble to cause the illumination of the tell-tale when perfectly steady strata 
are produced in tubes containing residual gases, we arranged the detector apparatus as 
shown in fig. 69. 
Fig. 69. 
A Z is the battery ; A being connected through the fluid resistances Fit Fit' 
(which can be plugged out of circuit by means of P and P'), the megohm, and the 
primary of coil No. 819, to the terminal T' of the tube ; A is also connected direct to 
one plate of the condenser C. Z is connected through the key K to the fluid 
resistance FR" (which can be plugged out by pressing down the key K'), thence to 
2 a 2 
