EXPERrMENTS IN ELFXTRICITY. 
ball of an insulated discharger quickly into contact with the 
ball of the jar, and then instantly withdrawing it. In describ- 
ing the experiments, I beg leave for the sake of copcisenesi, 
to call the wire communicating with the outside of the jar the 
negative, and that communicating with its inside the positive 
wire. 
Experiment 1. 
One of the pith balls was put in the groove nearly in con- 
tact with the extremity of the positive wire, and the jar was 
then cliarged'; when the discharge was made, the pith-ball 
instantly ran from the positive to the negative wire, where it 
stopped. 
Experiment 2- 
The pith-ball was phnced nearly in contact with the negative 
wire instead of the positive. On discharging the jar, the pith- 
ball ran from the negative to the positive wire, where it stopped. 
In this instance the ball moved in a direction exactly the con- 
trary to that in which it moved in the first experiment. 
Experiment 3. 
The pith-ball was placed exactly in the middle between the 
extremities of the two w'ires, which still remained at the same 
distance. 
When the discharge w'as made, the pith ball kept its place, 
and seemed not to be at all affected by it. 
Erpcriiiut 4. 
One pith-ball was placed, as in experiment 1, at the positive, 
and another, as in experiment 2, at the negative wire. On 
discharging the jar, the ball at the negative w'ire ran tow’ards 
the positive, and that at the positive ran towards the negative; 
the balls met exactly in the middle of the interval, and then 
stopped. 
This experiment adbrds a pleasing and striking instance of 
