LXIX
TO JARED ELIOT
Philadelphia, 13 February, 1750.
Dear Sir:
You desire to know my thoughts about the northeast storms beginning to leeward. Some years since, there was an eclipse of the moon at nine o’clock in the evening, which I intended to observe; but before night a storm blew up at northeast, and continued violent all night and all next day; the sky thick-clouded, dark, and rainy, so that neither moon nor stars could be seen. The storm did a great deal of damage all along the coast, for we had accounts of it in the newspapers from Boston, Newport, New York, Maryland, and Viriginia; but what surprised me was to find in the Boston newspapers an account of an observation of that eclipse made there; for I thought, as the storm came from the northeast, it must have begun sooner at Boston than with us, and consequently have prevented such observation. I wrote to my brother about it, and he informed me, that the eclipse was over there an hour before the storm began. Since which I have made inquiries from time to time of travellers, and of my correspondents northeastward and southwestward, and observed the accounts in the newspapers from New England, New York, Maryland, Virginia, and South Carolina; and I find it to be a constant fact, that northeast storms begin to leeward, and are often more violent there than farther to windward. Thus the last October storm, which with you was on the 8th, began on the 7th in Virginia and North Carolina, and was most violent there.
As to the reason of this, I can only give you my conjectures. Suppose a great tract of country, land and sea, to wit, Florida and the Bay of Mexico, to have clear weather for several days, and to be heated by the sun, and its air thereby exceedingly rarefied. Suppose the country northeastward, as Pennsylvania, New England, Nova Scotia, and Newfoundland, to be at the same time covered with clouds, and its air chilled and condensed. The rarefied air being lighter must rise, and the denser air next to it will press into its place; that will be followed by the next denser air, that by the next, and so on. Thus, when I have a fire in my chimney, there is a current of air constantly flowing from the door to the chimney; but the beginning of the motion was at the chimney, where the air being rarefied by the fire rising, its place was supplied by the cooler air that was next to it, and the place of that by the next, and so on to the door. So the water in a long sluice or mill-race, being stopped by a gate, is at rest like the air in a calm; but as soon as you open the gate at one end to let it out, the water next the gate begins first to move, that which is next to it follows; and so, though the water proceeds forward to the gate, the motion which began there runs backwards, if one may so speak, to the upper end of the race, where the water is last in motion. We have on this continent a long ridge of mountains running from northeast to southwest, and the coast runs the same course. These may, perhaps, contribute towards the direction of the winds, or at least influence them in some degree. If these conjectures do not satisfy you, I wish to have yours on the subject.
I doubt not but those mountains which you mention contain valuable mines, which time will discover. I know of but one valuable copper mine in this country, which is that of Schuyler’s in the Jerseys. This yields good copper, and has turned out vast wealth to the owners. I was at it last fall, but they were not then at work. The water is grown too hard for them, and they waited for a fire-engine from England to drain their pits. I suppose they will have that at work next summer; it costs them one thousand pounds sterling.
Colonel John Schuyler, one of the owners, has a deer park five miles round, fenced with cedar logs, five logs high, with blocks of wood between. It contains a variety of land, high and low, woodland and clear. There are a great many deer in it, and he expects in a few years to kill two hundred head a year, which will be a very profitable thing. He has likewise six hundred acres of meadow, all within bank. The mine is not far from Passaic Falls, which I went also to see. They are very curious; the water falls seventy feet perpendicularly, as we are told; but we had nothing to measure with.
It will be agreeable to you to hear that our subscription goes on with great success, and we suppose will exceed five thousand pounds of our currency. We have bought for the Academy the house that was built for itinerant preaching, which stands on a large lot of ground capable of receiving more buildings to lodge the scholars, if it should come to be a regular college. The house is one hundred feet long and seventy wide, built of brick, very strong, and sufficiently high for three lofty stories. I suppose the building did not cost less than two thousand pounds but we bought it for seven hundred and seventy-five pounds, eighteen shillings, eleven pence, and three farthings; though it will cost us three and perhaps four hundred more to make the partitions and floors and fit up the rooms. I send you enclosed a copy of our present constitution but we expect a charter from our Proprietaries this summer, when they may probably receive considerable alterations. The paper admonishes me that it is time to conclude.
I am, Sir,
Your obliged humble servant,
B. Franklin.
LXX
TO CADWALLADER COLDEN
Philadelphia, 28 June, 1750.
Sir:—
I wrote a line to you last post, and sent you some electrical observations and experiments. You formerly had those papers of mine, out of which something has been taken by Mr. Watson and inserted in the Transactions. If you have forgot the contents of those papers, I am afraid some things in that I last sent you will hardly be understood, as they depend on what went before. I send you herewith, my essay towards a new hypothesis of the cause and effects of lightning, &c., of which you may remember some hints in my first electrical minutes. I sent this essay above a twelvemonth since to Dr. Mitchell in London, and have since heard nothing of it, which makes me doubt of its getting to hand. In some late experiments, I have not only frequently fired unwarmed spirits by the electrical stroke, but have even melted small quantities of copper, silver, and gold; and not only melted, but vitrified them, so as to incorporate them with common glass; and this without any sensible heat, which strengthens my supposition, that the melting of metals by lightning may be a cold fusion. Of these experiments I shall shortly write a particular account. I wrote to Mr. Collinson, on reading in the Transactions the accounts from Italy and Germany, of giving purges, transferring odors, &c., with the electrical effluvia, that I was persuaded they were not true. He since informs me, that Abbé Nollet, of Paris, who had tried the experiments without success, was lately at the pains to make a journey to Turin, Bologna, and Venice, to inquire into the facts, and see the experiments repeated, imagining they had there some knacks of operating that he was unacquainted with; but, to his great disappointment, found little or no satisfaction, the gentleman there having been premature in publishing their imaginations and expectations for real experiments. Please to return me the papers when you have perused them.
My good old friend, Mr. Logan, being about three months since struck with a palsy, continues speechless, though he knows people, and seems in some degree to retain his memory and understanding. I fear he will not recover. Mr. Kalm is gone towards Canada again, and Mr. Evans is about to take a journey to Lake Erie, which he intends next week. Mr. Bartram continues well and hearty. I thank you for what you write concerning celestial observations. We are going on with our building for the Academy, and propose to have an observatory on the top; and, as we shall have a mathematical professor, I doubt not but we shall soon be able to send you some observations accurately made.
I am with great esteem and respect, &c.,
B. Franklin.
P. S.—If you think it would be agreeable to Mr. Alexander, or any other friend in New York, to peruse these electrical papers, you may return them to me through his hands.
LXXI
TO PETER COLLINSON
Philadelphia, 27 July, 1750.
Sir:—
Mr. Watson, I believe, wrote his Observations on my last paper in haste, without having first well considered the experiments, related in § 17, which still appear to me decisive in the question, Whether the accumulation of the electrical fire be in the electrified glass, or in the non-electric matter connected with the glass? and to demonstrate that it is really in the glass.
As to the experiment that ingenious gentleman mentions, and which he thinks conculsive on the other side, I persuade myself he will change his opinion of it when he considers that, as one person applying the wire of the charged bottle to warm spirits in a spoon held by another person, both standing on the floor, will fire the spirits, and yet such firing will not determine whether the accumulation was in the glass or the non-electric; so the placing another person between them, standing on wax, with a basin in his hand, into which the water from the phial is poured, while he at the instant of pouring presents a finger of his other hand to the spirits, does not at all alter the case; the stream from the phial, the side of the basin, with the arms and body of the person on the wax, being altogether but as one long wire, reaching from the internal surface of the phial to the spirits.
June 29th, 1751. In Captain Waddell’s account of the effects of lightning on his ship, I could not but take notice of the large comazants (as he calls them), that settled on the spintles at the top-mast heads, and burned like very large torches (before the stroke). According to my opinion, the electrical fire was then drawing off, as by points, from the cloud; the largeness of the flame betokening the great quantity of electricity in the cloud; and had there been a good wire communication from the spintle heads to the sea that could have conducted more freely than tarred ropes or masts of turpentine wood, I imagine there would either have been no stroke, or, if a stroke, the wire would have conducted it all into the sea without damage to the ship.
His compasses lost the virtue of the loadstone, or the poles were reversed, the north point turning to the south. By electricity we have (here at Philadelphia) frequently given polarity to needles, and reversed it at pleasure. Mr. Wilson, at London, tried it on too large masses and with too small force.
A shock from four large glass jars, sent through a fine sewing-needle, gives it polarity, and it will traverse when laid on water. If the needle, when struck, lies east and west, the end entered by the electric blast points north. If it lies north and south, the end that lay towards the north will continue to point north when placed on water, whether the fire entered at that end or at the contrary end.
The polarity given is strongest when the needle is struck lying north and south; weakest, when lying east and west. Perhaps if the force was still greater, the south end, entered by the fire (when the needle lies north and south), might become the north, otherwise it puzzles us to account for the inverting of compasses by lightning; since their needles must always be found in that situation, and by our little experiments, whether the blast entered the north and went out at the south end of the needle, or the contrary, still the end that lay to the north should continue to point north.
In these experiments the ends of the needle are sometimes finely blued, like a watch-spring, by the electric flame. This color, given by the flash from two jars only, will wipe off, but four jars fix it, and frequently melt the needles. I send you some that have had their heads and points melted off by our mimic lightning, and a pin that had its point melted off and some part of its head and neck run. Sometimes the surface on the body of the needle is also run, and appears blistered when examined by a magnifying-glass. The jars I make use of, hold seven or eight gallons, and are coated and lined with tin-foil; each of them takes a thousand turns of a globe nine inches diameter to charge it.
I send you two specimens of tin-foil melted between glass by the force of two jars only.
I have not heard that any of your European electricians have ever been able to fire gunpowder by the electric flame. We do it here in this manner: A small cartridge is filled with dry powder, hard rammed, so as to bruise some of the grains; two pointed wires are then thrust in, one at each end, the points approaching each other in the middle of the cartridge till within the distance of half an inch; then, the cartridge being placed in the circuit, when the four jars are discharged, the electric flame, leaping from the point of one wire to the point of the other within the cartridge amongst the powder, fires it, and the explosion of the powder is at the same instant with the crack of the discharge.
Yours, &c.,
B. Franklin.
LXXII
TO PETER COLLINSON
Philadelphia, 29 July, 1750.
Sir:—
As you first put us on electrical experiments by sending to our Library Company a tube with directions how to use it, and as our honorable proprietary enabled us to carry those experiments to a greater height by his generous present of a complete electrical apparatus, it is fit that both should know from time to time what progress we make. It was in this view I wrote and sent you my former papers on this subject, desiring that as I had not the honor of a direct correspondence with that bountiful benefactor to our library, they might be communicated to him through your hands. In the same view I write and send you this additional paper. If it happens to bring you nothing new (which may well be, considering the number of ingenious men in Europe continually engaged in the same researches), at least it will show that the instruments put into our hands are not neglected, and that if no valuable discoveries are made by us, whatever the cause may be, it is not want of industry and application.
I am, sir, your much obliged humble servant,
B. Franklin.
Opinions and Conjectures concerning the Properties and Effects of the Electrical Matter, and the Means of Preserving Buildings, Ships, &c., from Lightning, arising from Experiments and Observations made at Philadelphia, 1749.
§ 1. The electrical matter consists of particles extremely subtile, since it can permeate common matter, even the densest metals, with such ease and freedom as not to receive any perceptible resistance.
2. If any one should doubt whether the electrical matter passes through the substance of bodies, or only over and along their surfaces, a shock from an electrified large glass jar, taken through his own body, will probably convince him.
3. Electrical matter differs from common matter in this, that the parts of the latter mutually attract, those of the former mutually repel, each other. Hence the appearing divergency in a stream of electrified effluvia.
4. But, though the particles of electrical matter do repel each other, they are strongly attracted by all other matter.
5. From these three things, the extreme subtility of the electrical matter, the mutual repulsion of its parts, and the strong attraction between them and other matter, arises this effect, that, when a quantity of electrical matter is applied to a mass of common matter, of any bigness or length, within our observation (which hath not already got its quantity), it is immediately and equally diffused through the whole.
6. Thus, common matter is a kind of sponge to the electrical fluid. And as a sponge would receive no water, if the parts of water were not smaller than the pores of the sponge; and even then but slowly, if there were not a mutual attraction between those parts and the parts of the sponge; and would still imbibe it faster, if the mutual attraction among the parts of the water did not impede, some force being required to separate them; and fastest, if, instead of attraction, there were a mutual repulsion among those parts, which would act in conjunction with the attraction of the sponge; so is the case between the electrical and common matter.
7. But in common matter there is (generally) as much of the electrical as it will contain within its substance. If more is added, it lies without upon the surface, and forms what we call an electrical atmosphere; and then the body is said to be electrified.
8. It is supposed, that all kinds of common matter do not attract and retain the electrical with equal strength and force, for reasons to be given hereafter. And that those called electrics per se, as glass, &c., attract and retain it strongest, and contain the greatest quantity.
9. We know, that the electrical fluid is in common matter, because we can pump it out by the globe or tube. We know that common matter has near as much as it can contain, because, when we add a little more to any portion of it, the additional quantity does not enter, but forms an electrical atmosphere. And we know, that common matter has not (generally) more than it can contain, otherwise all loose portions of it would repel each other, as they constantly do when they have electric atmospheres.
10. The beneficial uses of this electric fluid in the creation we are not yet well acquainted with, though doubtless such there are, and those very considerable; but we may see some pernicious consequences that would attend a much greater proportion of it. For, had this globe we live on as much of it in proportion as we can give to a globe of iron, wood, or the like, the particles of dust and other light matters that get loose from it would, by virtue of their separate electrical atmospheres, not only repel each other, but be repelled from the earth, and not easily be brought to unite with it again; whence our air would continually be more and more clogged with foreign matter and grow unfit for respiration. This affords another occasion of adoring that wisdom which has made all things by weight and measure!
11. If a piece of common matter be supposed entirely free from electrical matter, and a single particle of the latter be brought nigh, it will be attracted and enter the body, and take place in the centre, or where the attraction is every way equal. If more particles enter, they take their places where the balance is equal between the attraction of the common matter and their own mutual repulsion. It is supposed they form triangles, whose sides shorten as their number increases, till the common matter has drawn in so many that its whole power of compressing those triangles by attraction is equal to their whole power of expanding themselves by repulsion; and then will such a piece of matter receive no more.
12. When part of this natural proportion of electrical fluid is taken out of a piece of common matter, the triangles formed by the remainder are supposed to widen, by the mutual repulsion of the parts, until they occupy the whole piece.
13. When the quantity of electrical fluid taken from a piece of common matter is restored again, it enters the expanded triangles, being again compressed till there is room for the whole.
14. To explain this: take two apples, or two balls of wood or other matter, each having its own natural quantity of the electrical fluid. Suspend them by silk lines from the ceiling. Apply the wire of a well-charged phial, held in your hand, to one of them (A) Plate III., Fig. 7, and it will receive from the wire a quantity of the electrical fluid, but will not imbibe it, being already full. The fluid, therefore, will flow round its surface and form an electrical atmosphere. Bring A into contact with B, and half the electrical fluid is communicated, so that each has now an electrical atmosphere, and therefore they repel each other. Take away these atmospheres, by touching the balls, and leave them in their natural state; then, having fixed a stick of sealing-wax to the middle of the phial to hold it by, apply the wire to A, at the same time the coating touches B. Thus will a quantity of the electrical fluid be drawn out of B, and thrown on A. So that A will have a redundance of this fluid, which forms an atmosphere round, and B an exactly equal deficiency. Now, bring these balls again into contact, and the electrical atmosphere will not be divided between A and B, into two smaller atmospheres as before; for B will drink up the whole atmosphere of A, and both will be found again in their natural state.
15. The form of the electrical atmosphere is that of the body it surrounds. This shape may be rendered visible in a still air, by raising a smoke from dry rosin dropt into a hot tea-spoon under the electrified body, which will be attracted, and spread itself equally on all sides, covering and concealing the body. And this form it takes, because it is attracted by all parts of the surface of the body, though it cannot enter the substance already replete. Without this attraction, it would not remain round the body, but dissipate in the air.
16. The atmosphere of electrical particles surrounding an electrified sphere is not more disposed to leave it, or more easily drawn off from any one part of the sphere than another, because it is equally attracted by every part. But that is not the case with bodies of any other figure. From a cube it is more easily drawn at the corners than at the plane sides, and so from the angles of a body of any other form, and still most easily from the angle that is most acute. Thus if a body shaped as A, B, C, D, E, in Plate III., Fig. 8, be electrified, or have an electrical atmosphere communicated to it, and we consider every side as a base on which the particles rest, and by which they are attracted, one may see, by imagining a line from A to F, and another from E to G, that the portion of the atmosphere included in F, A, E, G, has the line A, E for its basis. So the portion of atmosphere included in H, A, B, I, has the line A, B for its basis. And likewise the portion included in K, B, C, L, has B, C to rest on; and so on the other side of the figure. Now, if you will draw off this atmosphere with any blunt, smooth body, and approach the middle of the side A, B, you must come very near, before the force of your attractor exceeds the force or power with which that side holds the atmosphere. But there is a small portion between I, B, K, that has less of the surface to rest on, and to be attracted by, than the neighbouring portions, while at the same time there is a mutual repulsion between its particles and the particles of those portions; therefore here you can get it with more ease, or at a greater distance. Between F, A, H, there is a larger portion that has yet a less surface to rest on, and to attract it; here, therefore, you can get it away still more easily. But easiest of all, between L, C, M, where the quantity is largest, and the surface to attract and keep it back the least. When you have drawn away one of these angular portions of the fluid, another succeeds in its place from the nature of fluidity and the mutual repulsion before mentioned; and so the atmosphere continues flowing off at such angle, like a stream, till no more is remaining. The extremities of the portions of atmosphere over these angular parts are likewise at a greater distance from the electrified body, as may be seen by the inspection of the above figure; the point of the atmosphere of the angle C being much farther from C, than any other part of the atmosphere over the lines C, B, or B, A; and besides the distance arising from the nature of the figure, where the attraction is less, the particles will naturally expand to a greater distance by their mutual repulsion. On these accounts we suppose electrified bodies discharge their atmospheres upon unelectrified bodies more easily, and at a greater distance from their angles and points than from their smooth sides. Those points will also discharge into the air, when the body has too great an electrical atmosphere, without bringing any non-electric near to receive what is thrown off. For the air, though an electric per se, yet has always more or less water and other non-electric matters mixed with it; and these attract and receive what is so discharged.
17. But points have a property, by which they draw on as well as throw off the electrical fluid, at greater distances than blunt bodies can. That is, as the pointed part of an electrified body will discharge the atmosphere of that body, or communicate it farthest to another body, so the point of an unelectrified body will draw off the electrical atmosphere from an electrified body, farther than a blunter part of the same unelectrified body will do. Thus, a pin held by the head, and the point presented to an electrified body, will draw off its atmosphere at a foot distance; where, if the head were presented instead of the point, no such effect would follow. To understand this, we may consider that, if a person standing on the floor would draw off the electrical atmosphere from an electrified body, an iron crow and a blunt knitting-needle held alternately in his hand, and presented for that purpose, do not draw with different forces in proportion to their different masses. For the man, and what he holds in his hand, be it large or small, are connected with the common mass of unelectrified matter; and the force with which he draws is the same in both cases, it consisting in the different proportion of electricity in the electrified body and that common mass. But the force with which the electrified body retains its atmosphere by attracting it, is proportioned to the surface over which the particles are placed; that is, four square inches of that surface retain their atmosphere with four times the force that one square inch retains its atmosphere. And as in plucking the hairs from a horse’s tail a degree of strength not sufficient to pull away a handful at once could yet easily strip it hair by hair, so a blunt body presented cannot draw off a number of particles at once, but a pointed one, with no greater force, takes them away easily, particle by particle.
18. These explanations of the power and operation of points when they first occurred to me, and while they first floated in my mind, appeared perfectly satisfactory; but now I have written them, and considered them more closely, I must own I have some doubts about them; yet, as I have at present nothing better to offer in their stead, I do not cross them out; for, even a bad solution read, and its faults discovered, has often given rise to a good one, in the mind of an ingenious reader.
19. Nor is it of much importance to us to know the manner in which nature executes her laws; it is enough if we know the laws themselves. It is of real use to know that China left in the air unsupported will fall and break; but how it comes to fall, and why it breaks, are matters of speculation. It is a pleasure indeed to know them, but we can preserve our China without it.
20. Thus, in the present case, to know this power of points may possibly be of some use to mankind, though we should never be able to explain it. The following experiments, as well as those in my first paper, show this power. I have a large prime conductor, made of several thin sheets of clothier’s pasteboard, formed into a tube, near ten feet long and a foot diameter. It is covered with Dutch embossed paper, almost totally gilt. This large metallic surface supports a much greater electrical atmosphere than a rod or iron of fifty times the weight would do. It is suspended by silk lines, and when charged will strike, at near two inches distance, a pretty hard stroke, so as to make one’s knuckle ache. Let a person standing on the floor present the point of a needle, at twelve or more inches distance form it, and while the needle is so presented, the conductor cannot be charged, the point drawing off the fire as fast as it is thrown on by the electrical globe. Let it be charged, and then present the point at the same distance, and it will suddenly be discharged. In the dark you may see the light on the point, when the experiment is made. And if the person holding the point stands upon wax, he will be electrified by receiving the fire at that distance. Attempt to draw off the electricity with a blunt body, as a bolt of iron round at the end, and smooth (a silversmith’s iron punch, inch thick, is what I use), and you must bring it within the distance of three inches before you can do it, and then it is done with a stroke and crack. As the pasteboard tube hangs loose on silk lines, when you approach it with the punch-iron, it likewise will move towards the punch, being attracted while it is charged; but if, at the same instant, a point be presented as before, it retires again, for the point discharges it. Take a pair of large brass scales, of two or more feet beam, the cords of the scales being silk. Suspend the beam by a pack-thread from the ceiling, so that the bottom of the scales may be about a foot from the floor; the scales will move round in a circle by the untwisting of the pack-thread. Set the iron punch on the end upon the floor, in such a place as that the scales may pass over it in making their circle; then electrify one scale by applying the wire of a charged phial to it. As they move round, you see that scale draw nigher to the floor, and dip more when it comes over the punch; and if that be placed at a proper distance, the scale will snap and discharge its fire into it. But if a needle be stuck on the end of the punch, its point upward, the scale, instead of drawing nigh to the punch and snapping, discharges its fire silently through the point, and rises higher from the punch. Nay, even if the needle be placed upon the floor near the punch, its point upwards, the end of the punch, though so much higher than the needle, will not attract the scale and receive its fire, for the needle will get it and convey it away before it comes nigh enough for the punch to act. And this is constantly observable in these experiments, that the greater quantity of electricity on the pasteboard tube, the farther it strikes or discharges its fire, and the point likewise will draw it off at a still greater distance.
Now if the fire of electricity and that of lightning be the same, as I have endeavoured to show at large in a former paper, this pasteboard tube and these scales may represent electrified clouds. If a tube of only ten feet long will strike and discharge its fire on the punch at two or three inches distance, an electrified cloud of perhaps ten thousand acres may strike and discharge on the earth at a proportionably greater distance. The horizontal motion of the scales over the floor may represent the motion of the clouds over the earth; and the erect iron punch, a hill or high building; and then we see how electrified clouds passing over hills or high buildings at too great a height to strike, may be attracted lower till within their striking distance. And lastly, if a needle fixed on the punch with its point upright, or even on the floor below the punch, will draw the fire from the scale silently at a much greater than the striking distance, and so prevent its descending towards the punch; or if in its course it would have come nigh enough to strike, yet being first deprived of its fire it cannot, and the punch is thereby secured from the stroke; I say, if these things are so, may not the knowledge of this power of points be of use to mankind in preserving houses, churches, ships, &c., from the stroke of lightning, by directing us to fix on the highest parts of those edifices upright rods of iron made sharp as a needle, and gilt to prevent rusting, and from the foot of those rods a wire down the outside of the building into the ground, or down round one of the shrouds of a ship, and down her side till it reaches the water? Would not these pointed rods probably draw the electrical fire silently out of a cloud before it came nigh enough to strike, and thereby secure us from that most sudden and terrible mischief?
21. To determine the question whether the clouds that contain lightning are electrified or not, I would propose an experiment to be tried where it may be done conveniently. On the top of some high tower or steeple, place a kind of sentry-box (as in Plate I., Fig. 9), big enough to contain a man and an electrical stand. From the middle of the stand let an iron rod rise and pass bending out of the door, and then upright twenty or thirty feet, pointed very sharp at the end. If the electrical stand be kept clean and dry, a man standing on it when such clouds are passing low might be electrified and afford sparks, the rod drawing fire to him from a cloud. If any danger to the man should be apprehended (though I think there would be none), let him stand on the floor of his box, and now and then bring near to the rod the loop of a wire that has one end fastened to the leads, he holding it by a wax handle; so the sparks, if the rod is electrified, will strike from the rod to the wire and not affect him.
22. Before I leave this subject of lightning, I may mention some other similarities between the effects of that and those of electricity. Lightning has often been known to strike people blind. A pigeon that we struck dead to appearance by the electrical shock, recovering life, drooped about the yard several days, ate nothing, though crumbs were thrown to it, but declined and died. We did not think of its being deprived of sight, but afterwards a pullet, struck dead in like manner, being recovered by repeatedly blowing into its lungs, when set down on the floor ran headlong against the wall, and on examination appeared perfectly blind. Hence we concluded that the pigeon also had been absolutely blinded by the shock. The biggest animal we have yet killed, or tried to kill, with the electrical stroke was a well-grown pullet.
23. Reading in the ingenious Dr. Miles’s account of the thunder-storm at Stretham, the effect of the lightning in stripping off all the paint that had covered a gilt moulding of a pannel of wainscot without hurting the rest of the paint, I had a mind to lay a coat of paint over the filleting of gold on the cover of a book, and try the effect of a strong electrical flash sent through that gold from a charged sheet of glass. But having no paint at hand, I pasted a narrow strip of paper over it, and when dry sent the flash through the gilding, by which the paper was torn off from end to end with such force that it was broken in several places, and in others brought away part of the grain of the Turkey-leather in which it was bound, and convinced me that had it been painted the paint would have been stripped off in the same manner with that on the wainscot at Stretham.
24. Lightning melts metals, and I hinted in my paper on that subject that I suspected it to be a cold fusion; I do not mean a fusion by force of cold, but a fusion without heat. We have also melted gold, silver, and copper in small quantities by the electrical flash. The manner is this: Take leaf-gold, leaf-silver, or leaf-gilt copper, commonly called leaf-brass, or Dutch gold; cut off from the leaf long narrow strips the breadth of a straw. Place one of these strips between two strips of smooth glass that are about the width of your finger. If one strip of gold the length of the leaf be not long enough for the glass, add another to the end of it, so that you may have a little part hanging out loose at each end of the glass. Bind the pieces of glass together from end to end with strong silk thread; then place it so as to be part of an electrical circuit (the ends of gold hanging out being of use to join with the other parts of the circuit), and send the flash through it, from a large electrified jar or sheet of glass. Then, if your strips of glass remain whole, you will see that the gold is missing in several places, and instead of it a metallic stain on both the glasses; the stains on the upper and under glass exactly similar in the minutest stroke, as may be seen by holding them to the light; the metal appeared to have been not only melted, but even vitrified, or otherwise so driven into the pores of the glass, as to be protected by it from the action of the strongest aqua fortis or aqua regia. I send you enclosed two little pieces of glass with these metallic stains upon them, which cannot be removed without taking part of the glass with them. Sometimes the stain spreads a little wider than the breadth of the leaf, and looks brighter at the edge, as by inspecting closely you may observe in these. Sometimes the glass breaks to pieces; once the upper glass broke into a thousand pieces, looking like coarse salt. The pieces I send you were stained with Dutch gold. True gold makes a darker stain, somewhat reddish; silver, a greenish stain. We once took two pieces of thick looking-glass, as broad as a gunter’s scale, and six inches long; and, placing gold-leaf between them, put them between two smoothly-plained pieces of wood, and fixed them tight in a book-binder’s small press: yet, though they were so closely confined, the force of the electrical shock shivered the glass into many pieces. The gold was melted, and stained into the glass, as usual. The circumstances of the breaking of the glass differ much in making the experiment, and sometimes it does not break at all; but this is constant, that the stains in the upper and under pieces are exact counterparts of each other. And though I have taken up the pieces of glass between my fingers immediately after this melting, I never could perceive the least warmth in them.
25. In one of my former papers I mentioned that gilding on a book, though at first it communicated the shock perfectly well, yet failed after a few experiments, which we could not account for. We have since found, that one strong shock breaks the continuity of the gold in the filleting, and makes it look rather like dust of gold, abundance of its parts being broken and driven off; and it will seldom conduct above one strong shock. Perhaps this may be the reason: when there is not a perfect continuity in the circuit, the fire must leap over the vacancies; there is a certain distance which it is able to leap over according to its strength; if a number of small vacancies, though each be very minute, taken together exceed that distance, it cannot leap over them, and so the shock is prevented.
26. From the before-mentioned law of electricity, that points, as they are more or less acute, draw on and throw off the electrical fluid with more or less power, and at greater or less distances, and in larger or smaller quantities in the same time, we may see how to account for the situation of the leaf of gold suspended between two plates, the upper one continually electrified, the under one in a person’s hand standing on the floor. When the upper plate is electrified, the leaf is attracted and raised towards it, and would fly to that plate, were it not for its own points. The corner that happens to be uppermost when the leaf is rising, being a sharp point, from the extreme thinness of the gold, draws and receives at a distance a sufficient quantity of the electric fluid to give itself an electric atmosphere, by which its progress to the upper plate is stopped, and it begins to be repelled from that plate, and would be driven back to the under plate, but that its lowest corner is likewise a point, and throws off or discharges the overplus of the leaf’s atmosphere as fast as the upper corner draws it on. Were these two points perfectly equal in acuteness, the leaf would take place exactly in the middle space, for its weight is a trifle compared to the power acting on it; but it is generally nearest the unelectrified plate, because, when the leaf is offered to the electrified plate, at a distance, the sharpest point is commonly first affected and raised towards it; so that point, from its greater acuteness, receiving the fluid faster than its opposite can discharge it at equal distances, it retires from the electrified plate and draws nearer to the unelectrified plate, till it comes to a distance where the discharge can be exactly equal to the receipt, the latter being lessened and the former increased; and there it remains as long as the globe continues to supply fresh electrical matter. This will appear plain, when the difference of acuteness in the corners is made very great. Cut a piece of Dutch gold (which is fittest for these experiments on account of its great strength) into the form of Figure 10, the upper corner a right angle, the two next obtuse angles, and the lowest a very acute one; and bring this on your plate, under the electrified plate, in such a manner as that the right-angled part may be first raised (which is done by covering the acute part with the hollow of your hand), and you will see this leaf take place much nearer to the upper than the under plate; because, without being nearer, it cannot receive so fast at its right-angled point as it can discharge at its acute one. Turn this leaf with the acute part uppermost, and then it takes place nearest the unelectrified plate; because otherwise it receives faster at its acute point than it can discharge at its right-angled one. Thus the difference of distance is always proportioned to the difference of acuteness. Take care, in cutting your leaf, to leave no little ragged particles on the edges, which sometimes form points where you would not have them. You may make this figure so acute below and blunt above, as to need no under plate, it discharging fast enough into the air. When it is made narrower, as the figure between the pricked lines, we call it the golden fish, from its manner of acting. For if you take it by the tail, and hold it at a foot or greater horizontal distance from the prime conductor, it will, when let go, fly to it with a brisk but wavering motion, like that of an eel through the water; it will then take place under the prime conductor, at perhaps a quarter or half an inch distance, and keep a continual shaking of the tail like a fish, so that it seems animated. Turn its tail towards the prime conductor, and then it flies to your finger, and seems to nibble it. And if you hold a plate under it at six or eight inches distance, and cease turning the globe, when the electrical atmosphere of the conductor grows small, it will descend to the plate, and swim back again several times, with the same fish-like motion, greatly to the entertainment of spectators. By a little practice in blunting or sharpening the heads or tails of these figures, you may make them take place as desired, nearer or farther from the electrified plate.
27. It is said, in section eighth of this paper, that all kinds of common matter are supposed not to attract the electrical fluid with equal strength; and that those called electrics per se, as glass, &c., attract and retain it strongest, and contain the greatest quantity. This latter position may seem a paradox to some, being contrary to the hitherto received opinion; and therefore I shall now endeavour to explain it.
28. In order to this, let it first be considered that we cannot, by any means we are yet acquainted with, force the electrical fluid through glass. I know it is commonly thought that it easily pervades glass; and the experiment of a feather suspended by a thread, in a bottle hermetically sealed, yet moved by bringing a rubber tube near the outside of the bottle, is alleged to prove it. But if the electrical fluid so easily pervades glass, how does the phial become charged (as we term it), when we hold it in our hands? Would not the fire, thrown in by the wire, pass through to our hands, and so escape into the floor? Would not the bottle in that case be left just as we found it, uncharged, as we know a metal bottle so attempted to be charged would be? Indeed, if there be the least crack, the minutest solution of continuity in the glass, though it remains so tight that nothing else we know of will pass, yet the extremely subtile electric fluid flies through such a crack with the greatest freedom, and such a bottle we know can never be charged; what then makes the difference between such a bottle and one that is sound, but this, that the fluid can pass through the one and not through the other.
29. It is true there is an experiment that at first sight would be apt to satisfy a slight observer that the fire thrown into the bottle by the wire does really pass through the glass. It is this: Place the bottle on a glass stand under the prime conductor; suspend a bullet by a chain from the prime conductor till it comes within a quarter of an inch right over the wire of the bottle; place your knuckle on the glass stand at just the same distance from the coating of the bottle as the bullet is from its wire. Now let the globe be turned, and you see a spark strike from the bullet to the wire of the bottle, and the same instant you see and feel an exactly equal spark striking from the coating on your knuckle, and so on, spark for spark. This looks as if the whole received by the bottle was again discharged from it. And yet the bottle by this means is charged! And therefore the fire that thus leaves the bottle, though the same in quantity, cannot be the very same fire that entered at the wire, for if it were, the bottle would remain uncharged.
30. If the fire that so leaves the bottle be not the same that is thrown in through the wire, it must be fire that subsisted in the bottle (that is, in the glass of the bottle) before the operation began.
31. If so there must be a great quantity in glass, because a great quantity is thus discharged, even from very thin glass.
32. That this electrical fluid or fire is strongly attracted by glass, we know from the quickness and violence with which it is resumed by the part that had been deprived of it when there is an opportunity. And by this, that we cannot from a mass of glass draw a quantity of electric fire, or electrify the whole mass minus, as we can a mass of metal. We cannot lessen or increase its whole quantity, for the quantity it has it holds, and it has as much as it can hold. Its pores are filled with it as full as the mutual repellency of the particles will admit, and what is already in refuses, or strongly repels, any additional quantity. Nor have we any way of moving the electrical fluid in glass, but one: that is, by covering part of the two surfaces of thin glass with non-electrics, and then throwing an additional quantity of this fluid on one surface, which, spreading in the non-electric, and being bound by it to that surface, acts by its repelling force on the particles of the electrical fluid contained in the other surface, and drives them out of the glass into the non-electric on that side from whence they are discharged, and then those added on the charged side can enter. But when this is done there is no more in the glass, nor less, than before, just as much having left it on one side as it received on the other.
33. I feel a want of terms here, and doubt much whether I shall be able to make this part intelligible. By the word surface, in this case, I do not mean mere length and breadth without thickness; but, when I speak of the upper or under surface of a piece of glass, the outer or inner surface of the phial, I mean length, breadth, and half the thickness, and beg the favor of being so understood. Now I suppose that glass, in its first principles, and in the furnace, has no more of this electrical fluid than other common matter; that when it is blown, as it cools, and the particles of common fire leave it, its pores become a vacuum; that the component parts of glass are extremely small and fine, I guess from its never showing a rough face when it breaks, but always a polish; and from the smallness of its particles I suppose the pores between them must be exceedingly small, which is the reason that aqua fortis, nor any other menstruum we have, can enter to separate them and dissolve the substance; nor is any fluid we know of fine enough to enter, except common fire and the electric fluid. Now the departing fire, leaving a vacuum, as aforesaid, between these pores, which air nor water are fine enough to enter and fill, the electric fluid (which is everywhere ready in what we call the non-electrics, and in the non-electric mixtures that are in the air) is attracted in; yet does not become fixed with the substance of the glass, but subsists there as water in a porous stone, retained only by the attraction of the fixed parts, itself still loose and a fluid. But I suppose farther, that, in the cooling of the glass, its texture becomes closest in the middle, and forms a kind of partition, in which the pores are so narrow that the particles of the electrical fluid, which enter both surfaces at the same time, cannot go through, or pass and repass from one surface to the other, and so mix together; yet, though the particles of electric fluid imbibed by each surface cannot themselves pass through to those of the other, their repellency can, and by this means they act on one another. The particles of the electric fluid have a mutual repellency, but by the power of attraction in the glass they are condensed or forced near to each other. When the glass has received, and by its attraction forced closer together, so much of this electric fluid, as that the power of attracting and condensing in the one, is equal to the power of expansion in the other, it can imbibe no more, and that remains its constant whole quantity; but each surface would receive more, if the repellency of what is in the opposite surface did not resist its entrance. The quantities of this fluid in each surface being equal, their repelling action on each other is equal; and therefore those of one surface cannot drive out those of the other; but if a greater quantity is forced into one surface than the glass would naturally draw in, this increases the repelling power on that side, and, overpowering the attraction on the other, drives out part of the fluid that had been imbibed by that surface, if there be any non-electric ready to receive it; such there is in all cases where glass is electrified to give a shock. The surface that has been thus emptied, by having its electrical fluid driven out, resumes again an equal quantity with violence, as soon as the glass has an opportunity to discharge that over quantity more than it could retain by attraction in its other surface, by the additional repellency of which the vacuum had been occasioned. For experiments favoring (if I may not say confirming) this hypothesis, I must, to avoid repetition, beg leave to refer you back to what is said of the electrical phial in my former papers.
34. Let us now see how it will account for several other appearances. Glass, a body extremely elastic (and perhaps its elasticity may be owing in some degree to the subsisting of so great a quantity of this repelling fluid in its pores), must, when rubbed, have its rubbed surface somewhat stretched, or its solid parts drawn a little farther asunder, so that the vacancies, in which the electrical fluid resides, become larger, affording room for more of that fluid, which is immediately attracted into it from the cushion or handrubbing, they being supplied from the common stock. But the instant the parts of the glass so opened and filled have passed the friction, they close again, and force the additional quantity out upon the surface, where it must rest till that part comes round to the cushion again, unless some non-electric (as the prime conductor) first presents to receive it. But if the inside of the globe be lined with a non-electric, the additional repellency of the electrical fluid thus collected by friction on the rubbed part of the globe’s outer surface drives an equal quantity out of the inner surface into that non-electric lining, which, receiving it and carrying it away from the rubbed part into the common mass through the axis of the globe and frame of the machine, the new-collected electrical fluid can enter and remain in the outer surface, and none of it (or a very little) will be received by the prime conductor. As this charged part of the globe comes round to the cushion again, the outer surface delivers its overplus fire into the cushion, the opposite inner surface receiving at the same time an equal quantity from the floor. Every electrician knows that a globe wet within will afford little or no fire; but the reason has not before been attempted to be given, that I know of.
35. So, if a tube lined with a non-electric be rubbed, little or no fire is obtained from it; what is collected from the hand in the downward rubbing stroke entering the pores of the glass, and driving an equal quantity out of the inner surface into the non-electric lining; and the hand, in passing up to take a second stroke, takes out again what had been thrown into the outer surface, and then the inner surface receives back again what it had given to the non-electric lining. Thus the particles of electrical fluid belonging to the inside surface go in and out of their pores every stroke given to the tube. Put a wire into the tube, the inward end in contact with the non-electric lining, so it will represent the Leyden bottle. Let a second person touch the wire while you rub, and the fire, driven out of the inward surface when you give the stroke, will pass through him into the common mass, and return through him when the inner surface resumes its quantity, and therefore this new kind of Leyden bottle cannot be so charged. But thus it may: after every stroke, before you pass your hand up to make another, let a second person apply his finger to the wire, take the spark, and then withdraw his finger; and so on till he has drawn a number of sparks; thus will the inner surface be exhausted, and the outer surface charged; then wrap a sheet of gilt paper close round the outer surface, and grasping it in your hand you may receive a shock by applying the finger of the other hand to the wire; for now the vacant pores in the inner surface resume their quantity, and the overcharged pores in the outer surface discharge their overplus; the equilibrium being restored through your body, which could not be restored through the glass. If the tube be exhausted of air, a non-electric lining in contact with the wire is not necessary; for in vacuo the electrical fire will fly freely from the inner surface without a non-electric conductor; but air resists its motion; for being itself an electric per se, it does not attract it, having already its quantity. So the air never draws off an electric atmosphere from any body, but in proportion to the non-electrics mixed with it; it rather keeps such an atmosphere confined, which, from the mutual repulsion of its particles, tends to dissipation, and would immediately dissipate in vacuo. And thus the experiment of the feather enclosed in a glass vessel hermetically sealed, but moving on the approach of the rubbed tube, is explained. When an additional quantity of the electrical fluid is applied to the side of the vessel by the atmosphere of the tube, a quantity is repelled and driven out of the inner surface of that side into the vessel, and there affects the feather, returning again into its pores when the tube with its atmosphere is withdrawn; not that the particles of that atmosphere did themselves pass through the glass to the feather. And every other appearance I have yet seen, in which glass and electricity are concerned, are, I think, explained with equal ease by the same hypothesis. Yet perhaps it may not be a true one, and I shall be obliged to him that affords me a better.
36. Thus I take the difference between non-electrics and glass, an electric per se, to consist in these two particulars. 1st, that a non-electric easily suffers a change in the quantity of the electric fluid it contains. You may lessen its whole quantity by drawing out a part, which the whole body will again resume; but of glass you can only lessen the quantity contained in one of its surfaces; and not that, but by supplying an equal quantity at the same time to the other surface; so that the whole glass may always have the same quantity in the two surfaces, their two different quantities being added together. And this can only be done in glass that is thin; beyond a certain thickness we have yet no power that can make this change. And 2dly, that the electric fire freely moves from place to place in and through the substance of a non-electric, but not so through the substance of glass. If you offer a quantity to one end of a long rod of metal it receives it, and when it enters every particle that was before in the rod pushes its neighbour quite to the farther end, where the overplus is discharged; and this instantaneously, where the rod is part of the circle in the experiment of the shock. But glass, from the smallness of its pores, or stronger attraction of what it contains, refuses to admit so free a motion; a glass rod will not conduct a shock, nor will the thinnest glass suffer any particle entering one of its surfaces to pass through to the other.
37. Hence we see the impossibility of success in the experiments proposed to draw out the effluvial virtues of a non-electric, as cinnamon, for instance, and mixing them with the electric fluid, to convey them with that into the body by including it in the globe, and then applying friction, &c. For, though the effluvia of cinnamon and the electric fluid should mix within the globe, they would never come out together through the pores of the glass, and so go to the prime conductor, for the electric fluid itself cannot come through, and the prime conductor is always supplied from the cushion, and that from the floor. And besides, when the globe is filled with cinnamon, or other non-electric, no electric fluid can be obtained from its outer surface, for the reason before mentioned. I have tried another way, which I thought more likely to obtain a mixture of the electric and other effluvia together, if such a mixture had been possible. I placed a glass plate under my cushion, to cut off the communication between the cushion and the floor, then brought a small chain from the cushion into a glass of oil of turpentine, and carried another chain from the oil of turpentine to the floor, taking care that the chain from the cushion to the glass should touch no part of the frame of the machine. Another chain was fixed to the prime conductor, and held in the hand of a person to be electrified. The ends of the two chains in the glass were near an inch distant from each other, the oil of turpentine between. Now the globe being turned could draw no fire from the floor through the machine, the communication that way being cut off by the thick glass plate under the cushion; it must then draw it through the chains whose ends were dipped in the oil of turpentine. And as the oil of turpentine, being an electric per se, would not conduct, what came up from the floor was obliged to jump from the end of one chain to the end of the other, through the substance of that oil, which we could see in large sparks, and so it had a fair opportunity of seizing some of the finest particles of the oil in its passage, and carrying them off with it; but no such effect followed, nor could I perceive the least difference in the smell of the electric effluvia thus collected, from what it has when collected otherwise, nor does it otherwise affect the body of a person electrized. I likewise put into a phial, instead of water, a strong purgative liquid, and then charged the phial, and took repeated shocks from it, in which case every particle of the electrical fluid must, before it went through my body, have first gone through the liquid when the phial is charging, and returned through it when discharging, yet no other effect followed than if it had been charged with water. I have also smelled the electric fire when drawn through gold, silver, copper, lead, iron, wood, and the human body, and could perceive no difference; the odor is always the same, where the spark does not burn what it strikes; and therefore I imagine it does not take that smell from any quality of the bodies it passes through. And indeed, as that smell so readily leaves the electric matter, and adheres to the knuckle receiving the sparks, and to other things, I suspect that it never was connected with it, but arises instantaneously from something in the air acted upon by it. For if it was fine enough to come with the electric fluid through the body of one person, why should it stop on the skin of another?
But I shall never have done, if I tell you all my conjectures, thoughts, and imaginations on the nature and operations of this electric fluid, and relate the variety of little experiments we have tried. I have already made this paper too long, for which I must crave pardon, not having now time to abridge it. I shall only add that, as it has been observed here that spirits will fire by the electric spark in the summer-time without heating them, when Fahrenheit’s thermometer is above seventy; so, when colder, if the operator puts a small flat bottle of spirits in his bosom, or a close pocket, with the spoon, some little time before he uses them, the heat of his body will communicate warmth more than sufficient for the purpose.
ADDITIONAL EXPERIMENTS
Proving that the Leyden Bottle has no more Electrical Fire in it when charged than before, nor less when discharged; that, in discharging, the Fire does not issue from the Wire and the Coating at the same Time, as some have thought, but that the Coating always receives what is discharged by the Wire, or an equal Quantity; the outer Surface being always in a Negative State of Electricity, when the inner Surface is in a positive State.
Place a thick plate of glass under the rubbing cushion, to cut off the communication of electrical fire from the floor to the cushion; then, if there be no fine points or hairy threads sticking out from the cushion, or from the parts of the machine opposite to the cushion (of which you must be careful), you can get but a few sparks from the prime conductor, which are all the cushion will part with.
Hang a phial then on the prime conductor, and it will not charge, though you hold it by the coating. But—
Form a communication by a chain from the coating to the cushion, and the phial will charge.
For the globe then draws the electric fire out of the outside surface of the phial, and forces it through the prime conductor and wire of the phial into the inside surface.
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.
LXXIII
TO SAMUEL JOHNSON
Philadelphia, 23 August, 1750.
Dear Sir:—
We received your favor of the 16th instant. Mr. Peters will hardly have time to write to you by this post, and I must be short. Mr. Francis spent the last evening with me, and we were all glad to hear that you seriously meditate a visit after the middle of next month, and that you will inform us by a line when to expect you. We drank your health and Mrs. Johnson’s, remembering your kind entertainment of us at Stratford.
I think with you, that nothing is of more importance for the public weal, than to form and train up youth in wisdom and virtue. Wise and good men are, in my opinion, the strength of a state; much more so than riches or arms, which, under the management of ignorance and wickedness, often draw on destruction, instead of providing for the safety of the people. And though the culture bestowed on many should be successful only with a few, yet the influence of those few, and the service in their power may be very great. Even a single woman, that was wise, by her wisdom saved the city.
I think also that general virtue is more probably to be expected and obtained from the education of youth, than from the exhortation of adult persons; bad habits and vices of the mind being, like diseases of the body, more easily prevented than cured. I think, moreover, that talents for the education of youth are the gift of God; and that he on whom they are bestowed, whenever a way is opened for the use of them, is as strongly called as if he heard a voice from heaven; nothing more surely pointing out duty in a public service, than ability and opportunity of performing it.
I have not yet discoursed with Dr. Jenney concerning your removal hither. You have reason, I own, to doubt whether your coming on the foot I proposed would not be disagreeable to him, though I think it ought not; for, should his particular interest be somewhat affected by it, that ought not to stand in competition with the general good; especially as it cannot be much affected, he being old, and rich, and without children. I will, however, learn his sentiments before the next post. But whatever influence they might have on your determination about removing, they need have none on your intention of visiting; and if you favor us with the visit, it is not necessary that you should previously write to him to learn his disposition about your removal, since you will see him, and when we are all together those things may be better settled in conversation than by letters at a distance.
Your tenderness of the Church’s peace is truly laudable; but methinks to build a new church in a growing place is not properly dividing but multiplying; and will really be the means of increasing the number of those who worship God in that way. Many who cannot now be accommodated in the church go to other places or stay at home; and if we had another church, many who go to other places or stay at home would go to church. I suppose the interest of the church has been far from suffering in Boston by the building of two churches there in my memory. I had for several years nailed against the wall of my house a pigeon-box that would hold six pair; and though they bred as fast as my neighbours’ pigeons, I never had more than six pair, the old and strong driving out the young and weak, and obliging them to seek new habitations. At length I put up an additional box with apartments for entertaining twelve pair more, and it was soon filled with inhabitants by the overflowing of my first box and of others in the neighbourhood. This I take to be a parallel case with the building a new church here.
Your years I think are not so many as to be an objection of any weight, especially considering the vigor of your constitution. For the smallpox, if it should spread here, you might inoculate with great probability and safety; and I think that distemper generally more favorable here than farther northward. Your objection about the politeness of Philadelphia and your imagined rusticity is mere compliment, and your diffidence of yourself absolutely groundless.
My humble respects, if you please, to your brethren at the Commencement. I hope they will advise you to what is most for the good of the whole, and then I think they will advise you to remove hither. Please to tender my best respects and service to Mrs. Johnson and your son. I am, dear Sir, your obliged and affectionate humble servant,
B. Franklin.
LXXIV
TO JAMES BOWDOIN, AT BOSTON
Philadelphia, 25 October, 1750.
Sir:—
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.
LXXV
TO JARED ELIOT
Philadelphia, 25 October, 1750.
Dear Sir:—
I ought to have informed you sooner, that we got well home, and should have inquired after your health, as we left you in the hands of a fever. I beg you will excuse the delay, and desire you will remember in my favor the old saying, They who have much business must have much pardon. Whenever Mr. Francis and I meet of an evening, we drink your health, among our other New England friends, and he desires to be always respectfully remembered to you.
I am glad to hear you are got well again; but I cannot have the pleasure of seeing you again this year. I will write to Colonel Schuyler, and obtain for you a particular account of his manner of improving his banked grounds; and will also procure for you a specimen of our alum earth, with Mr. Syng’s observations on it. In return (for you know there is no trade without returns) I request you to procure for me a particular account of the manner of making a new kind of fence we saw at Southhold, on Long Island, which consists of a bank and hedge. I would know every particular relating to the matter, as the best thickness, height and slope of the bank; the manner of erecting it, the best time for the work, the best way of planting the hedge, the price of the work to laborers per rod or perch, and whatever may be of use for our information here, who begin in many places to be at a loss for wood to make fence with. We were told at Southhold, that this kind of fencing had been long practised with success at Southampton and other places, on the south side of the Island, but was new among them. I hear the minister at Southhold is esteemed an ingenious man; perhaps you may know him, and he will at your request favor me with an explicit account of these fences.
The fore part of the summer here was extremely dry, and the grass in many places was burnt up. But we had a good crop of wheat; and, rains coming on about the end of July, we had in August a new spring, the grass sprouting again wonderfully thick and fast, in fields where we thought the very roots had been destroyed. Our grave-diggers said they found the earth hot sensibly at three feet depth, even after these rains; perhaps the great heat below and the moisture above occasioned this sudden and profuse vegetation, the whole country being, as it were, one great hot-bed.
I am, with esteem and affection, dear Sir,
Your obliged humble servant,
B. Franklin.
LXXVI
TO A FRIEND IN BOSTON
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, 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.,
B. Franklin.
P. S.—The jars hold six gallons each.
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