Part 3

We see, when the air is _ground_ to pieces by an electrical machine, and _put_ into _sufficient motion_, by the _friction_ between the glass globe and the hand, a wire being hung from the iron barrel, so as very near to touch the ball, part of the _light_ issuing from the ball, as above described, _enters_ the wire, and is by it communicated to the iron barrel, and from thence _carried_ by _another wire_ to any distance, if not interrupted by some _non-electrical_ body: to the end of which, by a third wire is hung an egg; as soon as the globe is put in _motion_, and warm spirit of wine is placed so as to touch the egg, the spirit of wine will immediately take fire from the contact of the egg.

It has been already proved, that when the globe is put in _motion_, and your hand is applied to it, it _grinds_ to pieces the air between the globe and the hand, and so _rarefies_ and _expands_ it, and sends it off with great force, in the same manner, as _light_ is sent from any body of _fire in action_; as may be seen, if the electrical machine is set at work in the dark; when the emission from the glass globe will appear lucid.

The wires which are hung over the glass globe, by the _smallness_ of their _pores_, admitting nothing through them but _light_, and light being a body so _subtil_, as to penetrate the _pores_ of all other bodies, even to the very center of the earth; the _interstices_ of the _wires_ are filled with it from one end to the other.

As the _light_ is one continued body, throughout the whole extent of the wire, the _force_ it receives at the end next the glass globe, is _immediately_, and at the _same instant_ of time, communicated to the other end, let the _length_ or _extent_ of the wire be ever so great. As, for example, a pipe of any length, being filled with any sort of fluid, as water; if you force in more water at one end, the same moment, and in the same quantity, it will be forced out at the other.

By these experiments in electricity, we find that _fire_ and _light_ are produced as has been before observed, only by _breaking_ the air to pieces, and putting it in _motion_; and that _fire_ and _light_ are in _all_ bodies, water and ice not excepted; for, if a piece of ice is hung at the end of the wire, it will set fire to spirit of wine, as well as an egg.

The iron wire by the _closeness_ of its _pores_ prevents the surrounding air from entering it, and by that means at the same time forms a kind of _canal_ for the _light_ to pass through.

Having thus as I conceive, given a tolerable clear account, and, I hope, a true one, how and by what means, the various _phænomena_ in electricity are produced; I suppose, it will not be a very difficult task, to form a judgment, what disorders electrical operations are likely to be applied to, with hopes of service; as also in what others they are likely to be detrimental.

As the _heat_ and _redness_ of the _blood_, may be easily proved, to be in proportion to the _quantity_ and _motion_ of the _light_ it contains; so, wherever the blood is _heated_ to a great degree, as in _fevers_, _Inflammations_ of all kinds &c. there we are to expect the worst and most pernicious consequences, from the use of electricity.

But, on the contrary, as the nerves have been proved to act by a subtil fluid that passes through them, and that they, by the closeness of their pores, will not admit a fluid to pass through them, whose particles are much larger than those of _light_; the consequences we must often expect from such a make, must be obstructions; and as the _light_ in electricity is forced through our bodies and nerves, with great violence, it seems very reasonable to think, that where these obstructions are not too violent, there they may be broken through and removed by its power, of which we have had many instances, especially in palsies.

This is also confirmed by the success of the present practice of physick; for, the greatest relief, in these cases, is always found to proceed from _volatile_ and _penetrating_ medicines. But, care should be taken, not to administer electricity, to a person of weak and decayed nerves, instead of one whose nerves are obstructed.

_FINIS._

End of Project Gutenberg's A Treatise on Electricity, by Francis Penrose