adually less.
About the time all the electrons, which had left the grid and plate 1
of the condenser, have got home the plate current is back to the value
corresponding to _E_{C}_=_0_.

The plate current first increases and then decreases, but it doesn't
stop decreasing when it gets back to zero-grid value. And the reason is
all due to the habit forming tendencies of electrons in coils. To see
how this comes about, let's tell the whole story over again. In other
words let's make a review and so get a sort of flying start.

[Illustration: Fig 34]

When we close the battery switch, _S_ in Fig. 34, we allow a
current to flow in the plate circuit. This current induces a current in
the coil _cd_ and charges the condenser which is across it, making
plate 1 positive and plate 2 negative. A positive grid helps the plate
so that the current in the plate circuit builds up to the greatest
possible value as shown by the audion characteristic. That's the end of
the increase in current. Now the condenser discharges, sending electrons
through the coil _cd_ and making the grid less positive until
finally it is at zero potential, that is neither positive nor negative.

While the condenser is discharging the electrons in the coil _cd_
get a habit of flowing from _c_ toward _d_, that is from plate
2 to plate 1. If it wasn't for this habit the electron stream in
_cd_ would stop as soon as the grid had reduced to zero voltage.
Because of the habit, however, a lot of electrons that ought to stay on
plate 2 get hurried along and land on plate 1. It is a little like the
old game of "crack the whip." Some electrons get the habit and can't
stop quickly enough so they go tumbling into waiting-room 1 and make it
negative.

That means that the condenser not only discharges but starts to get
charged in the other direction with plate 1 negative and plate 2
positive. The grid feels the effect of all this, because it gets extra
electrons if plate 1 gets them. In fact the voltage effective between
grid and filament is always the voltage between the plates of the
condenser.

The audion characteristic tells us what is the result. As the grid
becomes negative it opposes the plate, shooing electrons back towards
the filament and reducing the plate current still further. But you have
already seen in my previous letter what happens when we reduce the
current in coil _ab_. There is then induced in coil _cd_ an
electron stream from _c_ to _d_. This indu