The Complete Works in Philosophy, Politics and Morals of the late Dr. Benjamin Franklin, Vol. 1 [of 3]

By Benjamin Franklin

Page 205

back on the prime conductor.

_Withdraw it, and they will diverge as much._

For the portion of atmosphere which they had lost, returns to them
again.


EXPERIMENT II.

_Excite the glass tube, and approach the prime conductor with
it, holding it across, near the end opposite to that on which
the threads hang, at the distance of five or six inches. Keep it
there a few seconds, and the threads of the tassels will diverge.
Withdraw it, and they will close._

They diverge, because they have received electric atmospheres
from the electric matter before contained in the substance of the
prime conductor; but which is now repelled and driven away, by the
atmosphere of the glass tube, from the parts of the prime conductor
opposite and nearest to that atmosphere, and forced out upon the
surface of the prime conductor at its other end, and upon the threads
hanging thereto. Were it any part of the atmosphere of the glass
tube that flowed over and along the prime conductor to the threads,
and gave them atmospheres (as is the case when a spark is given to
the prime conductor from the glass tube) such part of the tube's
atmosphere would have remained, and the threads continue to diverge;
but they close on withdrawing the tube, because the tube takes with
it _all its own atmosphere_, and the electric matter, which had
been driven out of the substance of the prime conductor, and formed
atmospheres round the threads, is thereby permitted to return to its
place.

_Take a spark from the prime conductor near the threads, when they
are diverged as before, and they will close._

For by so doing you take away their atmospheres, composed of the
electric matter driven out of the substance of the prime conductor,
as aforesaid, by the repellency of the atmosphere of the glass tube.
By taking this spark you rob the prime conductor of part of its
natural quantity of the electric matter; which part so taken is not
supplied by the glass tube, for when that is afterwards withdrawn, it
takes with it its whole atmosphere, and leaves the prime conductor
electrised negatively, as appears by the next operation.

_Then withdraw the tube, and they will open again._

For now the electric matter in the prime conductor, returning to its
equilibrium, or equal diffusion, in all parts of its substance, and
the prime conductor having lost some of its natural quantity, the
threads connected with it lose part of theirs, and so are electrised
negatively, and

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Text Comparison with Experiments and Observations on Electricity Made at Philadelphia in America

Page 2
As no more electrical fire can be thrown into the top of the bottle, when all is driven out of the bottom, so in a bottle not yet electrised, none can be thrown into the top, when none _can_ get out at the bottom; which happens either when the bottom is too thick, or when the bottle is placed on an electric _per se_.
Page 3
EXPERIMENT II.
Page 8
_ This experiment should be made in a closet where the air is very still.
Page 10
_ We suppose it was _driven off_, and not brought on thro' that wire; and that the machine and man, _&c.
Page 14
We judged then, that it must either be lost in decanting, or.
Page 17
On the principle, in s 7, that hooks of bottles, differently charged, will attract and repel differently, is made, an electrical wheel, that turns with considerable strength.
Page 21
CONTAINING OBSERVATIONS _and_ SUPPOSITIONS, _towards forming a new_ HYPOTHESIS, _for explaining the several_ Phaenomena _of_ THUNDER-GUSTS.
Page 22
11.
Page 25
--Let the two sets then represent two clouds, the one a sea cloud electrified, the other a land cloud.
Page 26
As currents of air, with the clouds therein, pass different ways, 'tis easy to conceive how the clouds, passing over each other, may attract each other, and so come near enough for the electrical stroke.
Page 27
In passing along leaf-gilding 'tis visible: for the leaf-gold is full of pores; hold a leaf to the light and it appears like a net; and the fire is seen in its leaping over the vacancies.
Page 32
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 electrised body, which will be attracted and spread itself equaly on all sides, covering and concealing the body.
Page 41
Turn its tail towards the prime conductor, and then it flies to your finger, and seems to nibble it.
Page 42
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.
Page 44
The particles of the electrical fluid have a mutual repellency, but by the power of attraction in the glass they are condensed or forced nearer to each other.
Page 45
For experiments favouring (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.
Page 46
[12] 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.
Page 49
Place a thick plate of glass under the rubbing cushion, to cut off the communication of.
Page 50
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.
Page 53
The Natural History of Mount Vesuvius, with the Explanation of the various Phenomena that usually attend the Eruptions of this celebrated Volcano.