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Entered according to the act of Congress, in the year one thousand eight

hundred and thirty-seven, by Hilliard, GRAY, AND Co., in the Clerk's Office of the District Court of the District of Massachusetts.

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arising from Experiments and Observations made

at Philadelphia, 1749. - Golden Fish. - Extrac-

tion of Emuvial Virtues by Electricity impracticable 227

Additional Experiments; proving that the Leyden Bot-

tle 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 Posi-

tive State

. 253

To James Bowdoin, at Boston. 25 October, 1750.

Enclosing Papers on Electricity

255

TO A FRIEND IN Boston. 25 December, 1750.

Account of an Accident while making an Electrical

Experiment

255

To James Bowdoin. 5 September, 1751.

Introducing Mr. Kinnersley as a Lecturer on Elec-

tricity

257

To CADWALLADER COLDEN. 1751.

Unlimited Nature of the Electric Force

258

Queries and Answers referred to in the foregoing Letter.

The Terms “ Electric

per

se and “ Non-elec-

tric” improper. – New Relation between Metals

and Water. — Effects of Air in Electrical Experi-

ments. — Experiment for discovering more of the

Qualities of the Electric Fluid .

259

JAMES BOWDOIN TO B. FRANKLIN. 21 Dec. 1751.

On the Causes of the crooked Direction of Light-

ning. - Objections to the Hypothesis that the Sea

is the Source of Lightning. - On the Swiftness of

the Electrical Fire

263

To James Bowdoin. 24 January, 1752.

Observations on the Subjects of the preceding Let-

ter. — Reasons for supposing the Sea to be the

grand Source of Lightning. – Reasons for doubting

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this Hypothesis. — Improvement in a Globe for

raising the Electric Fire

269

E. KINNERSLEY TO B. FRANKLIN. 3 February, 1752.

New Experiments. - Paradoxes inferred from them.

- Difference in the Electricity of a Globe of Glass

charged, and a Globe of Sulphur. - Difficulty of

ascertaining which is positive and which negative 273

To E. KINNERSLEY. 2 March, 1752.

Probable Cause of the different Attractions and

Repulsions of the two Electrified Globes mentioned

in the preceding Letter

275

James BowDOIN TO B. FRANKLIN. 2 March, 1752.

Effect of Lightning on Captain Waddel's Compass,

and on the Dutch Church at New York.

276

JAMES BOWDOIN TO B. FRANKLIN. 16 March, 1752.

Remarks on Dr. Colden's Letter respecting the

Electricity of the Clouds

279

To E. KINNERSLEY. 16 March, 1752.

.

Reasons for supposing that the Glass Globe charges

positively, and the Sulphur negatively. — Hint re-

specting a Leather Globe for Experiments when

travelling

280

To CADWALLADER Colden. 23 April, 1752.

Mistake, that only Metals and Water were Con-

ductors, rectified. — Supposition of a Region of

Electric Fire above our Atmosphere. — Theorem

concerning Light. - Poke-weed a Cure for Cancers 283

M. DALIBARD's Account of an Electrical Experiment at

Marly

288

ABBÉ MAZÉAS TO Stephen Hales. 20 May, 1752.

Giving a further Account of the Electrical Experi-

ment at Marly

293

To PETER COLLINSON. 19 October, 1752.

Electrical Kite

W. WATSON To The Royal Society. 21 Dec. 1752.

Concerning the Electrical Experiments in England

upon Thunder-clouds.

296

To James Bowdoin. 12 April, 1753.

On the Mode of coating Electrical Jars

299

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295

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