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ered but the probability of those rods preventing a stroke or explosion, which is only a part of the use I proposed for them; and the other part, their conducting a stroke, which they may happen not to prevent, seems to be totally forgotten, though of equal importance and advantage.
I thank you for communicating M. de Buffon's relation of the effect of lightning at Dijon, on the 7th of June last . In return, give me leave to relate an instance I lately saw of the same kind. Being in the town of Newbury in New England, in November last, I was shown the effect of lightning on their church, which had been struck a few months before. The steeple was a square tower of wood, reaching seventy feet up from the ground to the place where the bell hung, over which rose a taper spire, of wood likewise, reaching seventy feet higher, to the- vane of the weather-cock. Near the bell was fixed an iron hammer to strike the hours; and from the tail of the hammer a wire went down through a small gimlet-hole in the floor that the bell stood upon, and through a second floor in like manner; then horizontally under and near the plastered ceiling of that second floor, till it came near a plastered wall; then down by the side of that wall to a clock, which stood about twenty feet below the bell. The wire was not bigger than a common knittingneedle. The spire was split all to pieces by the lightning, and the parts flung in all directions over the square in which the church stood, so that nothing remained above the bell.
The lightning passed between the hammer and the clock in the abovementioned wire, without hurting either of the floors, or having any effect upon them (except making the gimlet-holes, through which the wire passed, a little bigger), and without hurting the plastered wall, or any part of the building, so far as the aforesaid wire and the pendulum-wire of the clock extended; which latter wire was about the thickness of a goose-quill. From the end of the pendulum, down quite to the ground, the building was exceedingly rent and damaged, and some stones in the foundation-wall torn out, and thrown to the distance of twenty or thirty feet . No part of the aforementioned long, small wire, between the clock and the hammer, could be found, except about two inches that hung to the tail of the hammer, and about as much that was fastened to the clock; the rest being exploded, and its particles dissipated in smoke and air, as gunpowder is by common fire, and had only left a black smutty track on the plastering, three or four inches broad, darkest in the middle, and fainter towards the edges, all along the ceiling, under which it passed, and down the wall. These were the effects and appearances; on which I would only make the few following remarks, viz.
1. That lightning, in its passage through a building, will leave wood to pass as far as it can in metal, and not enter the wood again till the conductor of metal ceases.
And the same I have observed in other instances, as to walls of brick or stone.
2. The quantity of lightning that passed through this steeple must have been very great, by its effects on the lofty spire above the bell, and on the square tower, all below the end of the clock-pendulum.
3. Great as this quantity was, it was conducted by a small wire and a clock-pendulum, without the least damage to the building so far as they extended.
4. The pendulum rod, being of a sufficient thickness, conducted the lightning without damage to itself; but the small wire was utterly destroyed.
5. Though the small wire was itself destroyed, yet it had conducted the lightning with safety to the building.
6. And from the whole it seems probable, that, if even such a small wire had been extended from the spindle of the vane to the earth, before the storm, no damage would have been done to the steeple by that stroke of lightning, though the wire itself had been destroyed. B. Franklin.
TO JOHN PRINGLE.*
On the Effects of Electricity in Paralytic Cases.
. Craven Street, 21 December, 1757.
In compliance with your request, I send you the following account of what I can at present recollect relating to the effects of electricity in paralytic cases, which have fallen under my observation.
Some years since, when the newspapers made mention of great cures performed in Italy and Germany by means of electricity, a number of paralytics were brought to me from different parts of Pennsylvania, and the neighbouring provinces, to be electrized, which I did for them at their request . My method was, to place the patient first in a chair, on an electric stool . and draw a number of large strong sparks from all parts of the affected limb or, side. Then I fully charged two six gallon glass jars, each of which had about three square feet of surface coated; and I sent the united shock of these through the affected limb or limbs, repeating the stroke commonly three times each day. The first thing observed, was an immediate greater sensible warmth in the lame limbs that had received the stroke than in the others; and the next morning the patients usually related, that they had in the night felt a pricking sensation in the flesh of the paralytic limbs; and would sometimes show a number of small red spots, which they supposed were occasioned by those prickings. The limbs, too, were found more capable of voluntary motion, and seemed to receive strength. A man, for instance, who could not the first day lift the lame hand from off his knee, would the next day raise it four or five inches, the third day higher; and, on the fifth day was able, but with a feeble, languid motion, to take off his hat. These appearances gave great spirits to the patients, and made them hope a perfect cure; but I do not remember, that I ever saw any amendment after the fifth day; which the patients perceiving, and finding the shocks pretty severe, they became discouraged, went home, and in a short time relapsed; so that I never knew any advantage from electricity in palsies, that was permanent. And how far the apparent, temporary advantage might arise from the exercise in the patients' journey, and coming daily to my house, or from the spirits given by the hope of success, enabling them to exert more strength in moving their limbs, 1 will not pretend to say.
* Afterwards Sir John Pringle, and President of the Royal Society. — Editor.
Perhaps some permanent advantage might have been obtained, if the electric shocks had been accompanied with proper medicine and regimen, under the direction of a skilful physician. It may be, too, that a few great strokes, as given in my method, may not be so proper as many small ones; since, by the account from Scotland of a case, in which two hundred shocks from a phial were given daily, it seems, that a perfect cure has been made. As to any uncommon strength supposed to be in the machine used in that case, I imagine it could have no share in the effect produced; since the strength of the shock from charged glass is in proportion to the quantity of surface of the glass coated; so that my shocks from those large jars must have been much greater than any that could be received from a phial held in the hand.
I am, with great respect, Sir,
Your most obedient servant,
TO THOMAS HUBBARD, AT BOSTON.
Electrical Apparatus. — Description of a Battery.
London, 28 April, 1758.
In pursuance of Mr. Winthrop's memorandum, which I lately received from you, through the hands of Mr. Mico, I have procured and delivered to him the following things, viz.
A mahogany case lined with lead, containing thirtyfive square glass bottles, in five rows, seven in a row.
A glass globe of the same size and kind with that I used at Philadelphia, and mounted in the same manner.
A large glass cylinder, mounted on an iron axis with brass caps; this form being most used here, and thought better than the globe, as a long, narrow cushion will electrify a greater surface at the same time.
The bottles have necks, which I think better than to be quite open; for so they would either be exposed to the dust and damp of the air, if they had no stoppers, or the stoppers would be too near together to admit of electrifying a single bottle, or row of bottles; there is only a little more difficulty in lining the inside with tinfoil, but that is chiefly got over by cutting it
Vol. v. 46 EE