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