2. At the same time that the wire and top of the bottle, &c. is electrised _positively_ or _plus_, the bottom of the bottle is electrised _negatively_ or _minus_, in exact proportion: _i. e._ whatever quantity of electrical fire is thrown in at top, an equal quantity goes out of the bottom. To understand this, suppose the common quantity of Electricity in each part of the bottle, before the operation begins, is equal to 20; and at every stroke of the tube, suppose a quantity equal to 1 is thrown in; then, after the first stroke, the quantity contain'd in the wire and upper part of the bottle will be 21, in the bottom 19. After the second, the upper part will have 22, the lower 18, and so on 'till after 20 strokes, the upper part will have a quantity of electrical fire equal to 40, the lower part none: and then the operation ends: for no more can be thrown into the upper part, when no more can be driven out of the lower part. If you attempt to throw more in, it is spued back thro' the wire, or flies out in loud cracks thro' the sides of the bottle. 3. The equilibrium cannot be restored in the bottle by _inward_ communication or contact of the parts; but it must be done by a communication formed _without_ the bottle, between the top and bottom, by some non-electric, touching both at the same time; in which case it is restored with a violence and quickness inexpressible: or, touching each alternately, in which case the equilibrium is restored by degrees. 4. As no more electrical fire can be thrown into the top of the bottle, when all is driven out of the bottom, so in a bottle not yet electrised, none can be thrown into the top, when none _can_ get out at the bottom; which happens either when the bottom is too thick, or when the bottle is placed on an electric _per se_. Again, when the bottle is electrised, but little of the electrical fire can be _drawn out_ from the top, by touching the wire, unless an equal quantity can at the same time _get in_ at the bottom. Thus, place an electrised bottle on clean glass or dry wax, and you will not, by touching the wire, get out the fire from the top. Place it on a non-electric, and touch the wire, you will get it out in a short time; but soonest when you form a direct communication as above.