The Complete Works in Philosophy, Politics and Morals of the late Dr. Benjamin Franklin, Vol. 2 [of 3]

By Benjamin Franklin

Page 98

a similar effect. The strong thriving state of
your mint, in putrid air, seems to shew, that the air is mended
by taking something from it, and not by adding to it. I hope this
will give some check to the rage of destroying trees that grow near
houses, which has accompanied our late improvements in gardening,
from an opinion of their being unwholesome. I am certain, from long
observation, that there is nothing unhealthy in the air of woods; for
we Americans have every where our country habitations in the midst
of woods, and no people on earth enjoy better health, or are more
prolific. ****

B. FRANKLIN.

FOOTNOTE:

[23] This extract is taken from Dr. Priestley's Experiments on
Air, Vol. I. page 94. It was written in answer to a note from Dr.
Priestley, informing our author of the result of certain experiments
on some plants which he had seen at Dr. Priestley's house in a very
flourishing state, in jars of highly noxious air. _Editor._




TO THE SAME[24].

_On the Inflammability of the Surface of certain Rivers in America._


_Craven-street, April 10, 1774._

DEAR SIR,

In compliance with your request, I have endeavoured to recollect the
circumstances of the American experiments I formerly mentioned to
you, of raising a flame on the surface of some waters there.

When I passed through New Jersey in 1764, I heard it several times
mentioned, that by applying a lighted candle near the surface of
some of their rivers, a sudden flame would catch and spread on the
water, continuing to burn for near half a minute. But the accounts I
received were so imperfect, that I could form no guess at the cause
of such an effect, and rather doubted the truth of it. I had no
opportunity of seeing the experiment; but calling to see a friend who
happened to be just returning home from making it himself, I learned
from him the manner of it; which was to choose a shallow place,
where the bottom could be reached by a walking-stick, and was muddy;
the mud was first to be stirred with the stick, and when a number
of small bubbles began to arise from it, the candle was applied.
The flame was so sudden and so strong, that it catched his ruffle
and spoiled it, as I saw. New Jersey having many pine-trees in many
parts of it, I then imagined that something like a volatile oil of
turpentine might be mixed with the waters from a pine-swamp, but this
supposition did not quite satisfy me. I mentioned the

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

Page 0
He was only apprized of the step that had been thus taken, while the first sheets were in the press, and time enough for him to transmit some farther remarks, together with a few corrections and additions, which are placed at the end, and may be consulted in the perusal.
Page 1
_July 28, 1747_.
Page 3
EXPERIMENT I.
Page 5
For, restoring the equilibrium in the bottle does not at all affect the Electricity in the man thro' whom the fire passes; that Electricity is neither increased nor diminish'd.
Page 8
Of the disposition and application of which wheels, and the various phaenomena resulting, I could, if I had time, fill you a sheet.
Page 9
And we daily in our experiments electrise bodies _plus_ or _minus_ as we think proper.
Page 10
--We encrease the force of the electrical kiss vastly, thus: Let _A_ and _B_ stand on wax; give one of them the electrised phial in hand; let the other take hold of the wire; there will be a small spark; but when their lips approach, they will be struck and shock'd.
Page 17
--But if another bottle which had been charged through the coating be placed near the same wheel, its wire will attract the thimble repelled by the first, and thereby double the force that carries the wheel round; and not only taking out the fire that had been communicated to the thimbles by the first bottle, but even robbing them of their natural quantity, instead of being repelled when they come again towards the first bottle, they are more strongly attracted, so that the wheel mends its pace, till it goes with great rapidity twelve or fifteen rounds in a minute, and with such strength, as that the weight of one hundred _Spanish_ dollars with which we once loaded.
Page 18
--This is called an electrical jack; and if a large fowl were spitted on the upright shaft, it would be carried round before a fire with a motion fit for roasting.
Page 20
Take a bottle in each hand, one that is electrify'd through the hook, the other through the coating: Apply the giving wire to the shot, which will electrify it _positively_, and the cork shall be repelled: Then apply the requiring wire, which will take out the spark given by the other; when the cork will return to the shot: Apply the same again, and take out another spark, so will the shot be electrify'd _negatively_; and the cork in that case shall be repelled equally as before.
Page 21
Chagrined a little that we have hitherto been able to produce nothing in this way of use to mankind; and the hot weather coming on, when electrical experiments are not so agreeable, 'tis proposed to put an end to them for this season, somewhat humorously, in a party of pleasure, on the banks of _Skuylkill_.
Page 23
18.
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Hence clouds formed by vapours raised from fresh waters within land, from growing vegetables, moist earth, &c.
Page 27
43.
Page 28
--For as whatever body can insinuate itself between the particles of metal, and overcome the attraction by which they cohere (as sundry menstrua can) will make the solid become a fluid, as well as fire, yet without heating it: so the electrical fire, or lightning, creating a violent repulsion between the particles of the metal it passes thro', the metal is fused.
Page 31
12.
Page 37
On the top of some high tower or steeple, place a kind of sentry-box, (as in FIG.
Page 47
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 entring one of its surfaces to pass thro' to the other.
Page 50
Now if the fire discharged from the inside surface of the bottle through its wire, remained on the prime conductor, the balls would be electrified and recede from each other.
Page 52
The History of Comets from the earliest Account of those kinds of Planets to the present Time; wherein the Sentiments of the Ancient and Modern Philosophers are occasionally displayed.