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a vast number of them may be drawn; but, if you take hold of the external surface with your hand, the phial will soon receive all the electric matter it is capable of, and the outside will then be entirely destitute of its electric matter, and no spark can be drawn from it by the finger; here, then, is a want of that effect which all bodies charged with the electricity have. Some of the effects of an electric body, which I suppose the Abbe has observed in the exterior surface of a charged phial are, that all light bodies are attracted by it. This is an effect which I have constantly observed, but do not think that it proceeds from an attractive quality in the exterior surface of the phial, but in those light bodies themselves, which seem to be attracted by the phial. It is a constant observation, that, when one body has a greater charge of electric matter in it than another (that is, in proportion to the quantity they will hold), this body will attract that which has less; now, I suppose, and it is a part of Mr. Franklin's system, that all those light bodies, which appear to be attracted, have more electric matter in them than the external surface of the phial has; wherefore they endeavour to attract the phial to them, which is too heavy to be moved by the small degree of force they exert, and yet, being greater than their own weight, moves them to the phial. The following experiment will help the imagination in conceiving this. Suspend a cork ball, or a feather, by a silk thread, and electrize it; then bring this ball nigh to any fixed body, and it will appear to be attracted by that body, for it will fly to it; now, by the consent of electricians, the attractive cause is in the ball itself, and not in the fixed body to which it flies; this is a similar case with the apparent attraction of light bodies, to the external surface of a charged phial.
The Abbe says, (p. 69,) "that he can electrize a hundred men, standing on wax, if they hold hands, and if one of them touch one of these surfaces (the exterior) with the end of his finger." This I know he <;an, while the phial is charging; but, after the phial is charged, I am as certain he cannot; that is, hang a phial, prepared for the Leyden experiment, to the conductor, and let a man, standing on the floor, touch the coating with his finger, while* the globe is turned, till the electric matter spews out of the hook of the phial, or some part of the conductor, which I take to be the certainest sign that the phial has received all the electric matter it can; after this appears, let the man, who before stood on the floor, step on a cake of wax, where he may stand for hours, and the globe all that time turned, and yet have no appearance of being electrized. After the electric matter was spewed out as above from the hook of the phial prepared for the Leyden experiment, I hung another phial, in like manner prepared, to a hook fixed in the coating, of the first, and held this other phial in my hand; ,now, if there was any electric matter transmitted through the glass of the first phial, the second one would certainly receive and collect it; but, having kept the phials in this situation for a considerable time, during which the globe was continually turned, I could not perceive that the second phial was in the least charged, for, when I touched the hook with my finger, as in the Leyden experiment, I did not feel the least commotion, nor perceive any spark to issue from the hook.
I likewise made the following experiment; having charged two phials (prepared for the Leyden experiment) through their hooks, two persons took each one of these phials in their hand; one held his phial by the coating, the other by the hook, which he could do by removing the communication from the bottom before he took hold of the hook. These persons placed themselves one on each side of me, while I stood on a cake of wax, and took hold of the hook of that phial which was held by its coating (upon which a spark issued, but the phial was not discharged, as I stood on wax); keeping hold of the hook, -1 touched the coating of the phial that was held by its hook with my other hand, upon which there was a large spark to be seen between my ringer and the coating, and both phials were instantly discharged. If the Abbe's opinion be right, that the exterior surface, communicating with the coating, is charged, as well as the interior, communicating with the hook; how can I, who stand on wax, -discharge both these phials, when it is well known I could not discharge one of them singly? Nay, suppose I have drawn the electric matter from both of them, what becomes of it 1 For I appear to have no additional quantity in me when the experiment is over, and I have not stirred off the wax; wherefore this experiment fully convinces me, that the exterior surface is not charged; and not only so, but that it wants as much electric matter as the inner has of excess; for by this supposition, which is a part of Mr. Franklin's system, the above experiment is easily accounted for, as follows.
When I stand on wax, my body is not capable of receiving all the electric matter from the hook of one phial, which it is ready to give; neither can it give as much to the coating of the other phial as it is ready to take, when one' is only applied to me; but, when both are applied, the coating takes from me what the hook gives; thus I receive the fire from the first phial at B, the exterior surface of which is supplied from the hand at A; I give the fire to the second phial at C, whose interior surface is discharged by the hand at D. This discharge at D may be made evident by receiving that fire into the hook of a third phial, which is done thus. In place of taking the hook of the second phial in your hand, run the wire of a third phial, prepared as for the Leyden experiment, through it, and hold this third phial in your hand, the second one hanging to it, by the ends of the hooks run through each other; when the experiment is performed, this third phial receives the fire at D, and will be charged.
When this experiment is considered, I think, it must fully prove, that the exterior surface of a charged phial wants electric matter, while the inner surface has an excess of it. One thing more worthy of notice in this experiment is, that I feel no commotion or shock in my arms, though so great a quantity of electric matter passes them instantaneously; I only feel a pricking in the ends of my fingers. This makes me think the Abbe has mistook, when he says, that there is no difference between the shock felt in performing the Leyden experiment, and the pricking felt on drawing simple sparks, except that of greater to less. In the last experiment, as much electric matter went through my arms, as would have given me a very sensible shock, had there been an immediate communication, by my arms, from the hook to the coating of the same phial; because, when it was taken into a third phial, and that phial discharged singly through ray arms, it gave me a sensible shock. If these experiments prove, that the
VOL. V. BB
electric matter does not pass through the entire thickness of the glass, it is a necessary consequence that it must always come out where it entered.
The next thing I meet with is in the Abbe's fifth letter, (p. 88,) where he differs from Mr. Franklin, who thinks that the whole power of giving a shock is in the glass itself, and not in the non-electrics in contact with it. The experiments which Mr. Franklin gave to prove this opinion, in his Observations on the Leyden Bottle, (p. 189,) convinced me that he was in the right; and what the Abbe has asserted, in contradiction thereto, has not made me think otherwise. The Abbe, perceiving, as I suppose, that the experiments, as Mr. Franklin had performed them, must prove his assertion, alters them without giving any reason for it, and makes them in a manner that proves nothing. Why will he have the phial, into which the water is to be decanted from a charged phial, held in a man's hand? If the power of giving a shock is in the water contained in the phial, it should remain there, though decanted into another phial, since no non-electric body touched it to take that power off. The phial being placed on wax is no objection, for it cannot take the power from the water, if it had any, but it is a necessary means to try the fact; whereas, that phial's being charged when held in a man's hand, only proves, that water will conduct the electric matter. The Abbe owns, (p. 94,) that he had heard this remarked, but says, Why is not a conductor of electricity an electric subject? This is not the question; Mr. Franklin never said, that water was not an electric subject; he said, that the power of giving a shock was in the glass, and not in the water; and this his experiments fully prove; so fully, that it may appear impertinent to offer any more; yet, as I do not know that the following has been taken