Thus the bottle is charged with its own fire, no other being to be had while the glass plate is under the cushion.

Hang two cork balls by flaxen threads to the prime conductor; then touch the coating of the bottle, and they will be electrified and recede from each other.

For, just as much fire as you give the coating, so much is discharged through the wire upon the prime conductor, whence the cork balls receive an electrical atmosphere. But,

Take a wire bent in the form of a C, with a stick of wax fixed to the outside of the curve, to hold it by; and apply one end of this wire to the coating, and the other at the same time to the prime conductor, the phial will be discharged; and, if the balls are not electrified before the discharge, neither will they appear to be so after the discharge, for they will not repel each other.

If the phial really exploded at both ends, and discharged fire from both coating and wire, the balls would be more electrified, and recede farther; for none of the fire can escape, the wax handle preventing.

But if the fire with which the inside surface is surcharged, be so much precisely as is wanted by the outside surface, it will pass round through the wire fixed to the wax handle, restore the equilibrium in the glass, and make no alteration in the state of the prime conductor.

Accordingly we find, that, if the prime conductor be electrified, and the cork balls in a state of repellency before the bottle is discharged, they continue so afterwards. If not, they are not electrified by that discharge.

SIR,

TO JAMES BOWDOIN,* AT BOSTON.

Enclosing Papers on Electricity.

Philadelphia, 25 October, 1750.

Enclosed with this I send you all my electrical papers, fairly transcribed, and I have, as you desired, examined the copy and find it correct. I shall be glad to have your observations on them; and, if in any part I have not made myself well understood, I will, on notice, endeavour to explain the obscure passages by letter. My compliments to Mr. Cooper, and the other gentlemen, who were with you here. I hope you all got safe home. I am, Sir,

Your most humble servant,

B. FRANKLIN.

TO A FRIEND IN BOSTON.†

Account of an Accident while making an Electrical Experiment.

Philadelphia, 25 December, 1750.

I have lately made an experiment in electricity, that I desire never to repeat. Two nights ago, being about to kill a turkey by the shock from two large glass jars,

Mr. Bowdoin was at this time twenty-three years old. He became distinguished afterwards as a philosopher and statesman, being one of the principal founders and the first president of the American Academy of Arts and Sciences. He took an active and prominent part in the events of the American Revolution, and was subsequently governor of Massachusetts. EDITOR.

A copy of this letter was found among Governor Bowdoin's papers, without the name of the person to whom it was addressed. EDITOR.

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containing as much electrical fire as forty common phials, I inadvertently took the whole through my own arms and body, by receiving the fire from the united top wires with one hand, while the other held a chain connected with the outsides of both jars. The company present (whose talking to me, and to one another, I suppose occasioned my inattention to what I was about) say, that the flash was very great, and the crack as loud as a pistol; yet, my senses being instantly gone, I neither saw the one nor heard the other; nor did I feel the stroke on my hand, though I afterwards found it raised a round swelling where the fire entered, as big as half a pistol-bullet; by which you may judge of the quickness of the electrical fire, which by this instance seems to be greater than that of sound, light, or animal sensation.

What I can remember of the matter is, that I was about to try whether the bottles or jars were fully charged, by the strength and length of the stream issuing to my hand, as I commonly used to do, and which I might safely enough have done if I had not held the chain in the other hand. I then felt what I know not how well to describe; a universal blow throughout my whole body from head to foot, which seemed within as well as without; after which the first thing I took notice of was a violent quick shaking of my body, which gradually remitting, my sense as gradually returned, and then I thought the bottles must be discharged, but could not conceive how, till at last I perceived the chain in my hand, and recollected what I had been about to do. That part of my hand and fingers, which held the chain, was left white, as though the blood had been driven out, and remained so eight or ten minutes after, feeling like dead flesh; and I had a numbness in my arms and the back of my neck,

which continued till the next morning, but wore off. Nothing remains now of this shock, but a soreness in my breast-bone, which feels as if it had been bruised. I did not fall, but suppose I should have been knocked down, if I had received the stroke in my head. The whole was over in less than a minute.

You may communicate this to Mr. Bowdoin, as a caution to him, but do not make it more public, for I am ashamed to have been guilty of so notorious a blunder; a match for that of the Irishman, whom my sister told me of, who, to divert his wife, poured the bottle of gunpowder on the live coal; or of that other, who, being about to steal powder, made a hole in the cask with a hot iron. I am yours, &c.

As you are curious in electricity, I take the freedom of introducing to you, my friend Mr. Kinnersley, who visits Boston with a complete apparatus for experimental lectures on that subject. He has given great satisfaction to all that have heard him here, and I believe you will be pleased with his performance. He is quite a stranger in Boston; and, as you will find him a sensible, worthy man, I hope he will be favored with your countenance, and the encouragement which that must procure him among your friends. I am, Sir, with great respect, Your most humble servant,

B. FRANKLIN.

VOL. V.

17a

TO CADWALLADER COLDEN,* AT NEW YORK

COMMUNICATED TO MR. COLLINSON.

Unlimited Nature of the Electric Force.

SIR,

Philadelphia, 1751.

I enclose you answers, such as my present hurry of business will permit me to make, to the principal queries contained in yours of the 28th instant, and beg leave to refer you to the latter piece in the printed collection of my papers, for farther explanation of the difference between what are called electrics per se and non-electrics. When you have had time to read and consider these papers, I will endeavour to make any new experiments you shall propose, that you think may afford farther light or satisfaction to either of us; and shall be much obliged to you for such remarks, objections, &c., as may occur to you.

I forget whether I wrote to you, that I have melted brass pins and steel needles, inverted the poles of the magnetic needle, given a magnetism and polarity to needles that had none, and fired dry gunpowder by the electric spark. I have five bottles that contain eight or nine gallons each, two of which charged are sufficient for those purposes; but I can charge and discharge them altogether. There are no bounds (but what expense and labor give) to the force man may raise and use in the electrical way; for bottle may be added to

* Afterwards lieutenant-governor of New York. He was highly distinguished for his attainments in medicine, the mathematics, botany, and the philosophical sciences, and wrote several papers on those subjects, which were published in Europe. He also wrote a history of the Five Nations of Indians. He lived to an advanced age, and died at the be. ginning of the American Revolution. - EDITOR.