the circuit, and myself in another part of it. When the jar is charged to the usual high intensity, I will operate in the capacity of discharging-rod, by presenting the brass ball which I hold in my hand towards the ball of the jar. The result is the simultaneous discharge of the six pieces of ordnance, but not the slightest shock is experienced by myself, although the electric fluid that discharged the guns traversed my arms and chest, prior to its arriving at them.

Glass tubes, filled with water, have been employed in place of the wet string, in the process of firing gunpowder by electric discharges; but if the tube be too wide, the electro-momentum would be too great for any person to stand in the circuit without experiencing a severe blow; and even by long use of a narrow tube the electric momentum becomes too great for any person to stand in its way. I have employed a glass tube of narrow bore for several successive years, but I found that it gradually augmented the velocity of the transinitted electric fluid, till eventually I could not ignite gunpowder by its use : unless, indeed, I considerably augmented the quantity of Auid transmitted. This circumstance, I afterwards found, was owing to the nitric acid that had been formed by previous discharges, from the atmospheric air which the water held in solution, thus increasing its conduction, and giving greater freedom to the electric transmisssion.

This fact, which I have not seen mentioned in any other place, would not happen if a new portion of water were employed in every experiment, and the inside of the tube well cleaned.

' Another fact that I sometimes meet with, when operating on gunpowder, is that of setting the string on fire, at one or both of its ends, when they happen to get too dry by previous discharges.

Shortly after the discovery of electro-magnetism was made known in England, Sir Humphrey Davy magnetized steel needles by electrical discharges from a battery of Leyden jars; as will be seen by a reference to his excellent paper in these Annals.* But I am not aware that those experiments were ever varied by a change in the character of the circuit, prior to those which I published in 1826, in the Phil. Magazine. By those experiments I showed that, unless the electric fluid has a considerable momentum, steel needles are not magnetized by its influence whilst traversing a circuit from the Leyden jar.t

• Vol. vii. † See the first and second papers in No. 47, of these Annals.

EDITORIAL NOTICES.

We have heard nothing further respecting the enquiries of T. H. than that our letter, a copy of which appears

at

page 221, Vol. 6, had been received. The Editor of the Nautical Magazine, merely acknowledged it on the cover of his No. for April, 1841. The “Reviews" which Mr. B. thinks necessary to be continued, are

not lost sight of. We have a long time ago been advised, by one of the first chemical philosophers in the land, to carry them on in regular series. Want of time alone, has prevented us undertaking the arduous task. We are aware of the importance of such an undertaking were it for no other purpose than that of exhibiting, to the writer of those papers, the propriety and importance of rectitude, candour, and consistency. We are of opinion that a series of commentaries, properly conducted, and in the same order that the papers have appeared, would be exceedingly interesting.

Dr. Faraday has refused answering Dr. Hare's second letter, Annals, Vol. 7, p. 351, and declined any further public discussion with him on the points at issue.--Silliman's American Journal.

Prize Volumes for the latter half year of 1842. 1st. For the paper descriptive of a more powerful and economical voltaic battery than any, at present, known. The test to be, decomposition of acidulated water, with the terminal metals at one inch asunder.

2nd. For another voltaic battery; conditions as before. Test, the decomposition of pure water, with terminals four inches asunder

3rd. For a thermo-electric battery, superior to any now known, differently constructed, and more economical. Test, the ignition of the greatest length of platinum wire, of both of an inch diameter.

4th. For any magnet that will suspend 1 cwt., with the cross-piece at one inch distance from the poles.

END OF VOLUME EIGHT.

INDEX TO VOLUME EIGHT.

Page.

A.
Adams, Dr. Samuel, his Experiments and Observations on
Light

384
Agassiz, Professor, on an undescribed species of Sturgeon 210
Airy, Professor, Astronomer Royal, on Magnetic Variation

119
Ampére, M.

337
Arago, M., on Electro-Gilding

217
Armstrong, Mr.

353
Artesian Wells

498
Apjohn, Dr., on Pyrope

213
on the Diurnal Fluctuations of the Barometer 209
on the Voltaic Pile

210
Arria, M., on the Induction of Electric Currents

381
Asphyxia, on the Treatment of

234
Audible Sounds, on the Production of

209

49

21

B.
Beccaria, Father Gimbatista

180
Bache, Professor

).
Ballard, Professor M., on Bioxalate of Ammonia
Ball, Mr., on an undescribed species of Sturgeon

210
Barlow, Professor

337, 341
Bante, M., on Electro-Gilding

217
Barnard, Professor, F.A.P., on the Daguerreotype Process 255
Barometer, Diurnal Fluctuations of

209
Bassett, John, Esq., M.P., on the Machinery for Raising Miners 237
Becquerel, M., his Balance Electrometer

(Note). 18
on Jacobi's Theory

Edmund, on the Constant Voltaic Battery 454
Bennet, the Rev. Abraham, on Electricity by Evaporation 354

by Simple Contact 422

his Electrical Experiments 377
Bergem, M., on Electro-Gilding

216
Berzelius, Professor, on the Voltaic Theory

80
Bichlorure of Sulphur, &c.

493
Bichromate of Potassa in Voltaic Batteries

415
Bioxalate of Ammonia, Decomposition of

49
Blee, Mr. Robert, Jun., on the Longevity of Miners

232
Boettiger, M., on Electro-Gilding

218
Bouvard, M. E., on Shooting Stars

283

Buff, Dr., on the Voltaic Pile

on Quantity and Intensity in Ditto

Page.

57
74

C.

Calotype Paper, on the Preparation of

414, 496
Camphor, its Movements on Water

390, 417
Cavallo, Tiberius, Esq., on Electricity by Evaporation

182, 363
Chevet, Professor F., on Bichlorure of Sulphur, &c.

493
Christie, Professor S. Hunter

340
Clibborn, C., Esq., on the Leyden Jar

214
Compass, Variation of, at Greenwich

119
Conlomb's Law

17
Conch, Jonathan, Esq., on the Pilchard Fishery

232
Couronne des Tasses

370
Courtney, M. J. S., on the Pilchard Fishery

232
Crosse, Andrew, Esq., on the Perforation of Glass by Electricity 327

D.
Daguerreotype, Process of

255
Daniell, Professor, his Reclamation of the “ Constant Voltaic
Battery"

456
Davy, Sir Humphrey

(22, Note). 337
his Bakerian Lecture

428
Delamethrie, M. J. C., Volta's Letter to

371
De la Rive, Professor, on Electro-Gilding

216, 333
his Voltaic Experiments

242
De Luc, M. J. A., his Analysis of the Voltaic Pile

427
his Dry Electric Column

448
Dorin, M., on Electro-Gilding

217
Dry Electric Column

484
Dublin, Archbishop of, on a remarkable Meteor

210
Dumas, M.

315
Dunkin, Mr.

113
Dutrochet, M., his Obervations on Camphor

393
Dyckhoff, M., on the Activity of the Voltaic Pile

378
made the first Dry Pile

. 378

447,

49,

E.
Ebelmen, M., on the Vapours of Furnaces

336
Electric Etching

415
Electric Column, the first Dry One

378
the first with Dry Paper

379
De Luc's

448
Electric Currents, Induced

472
on the Induction of

381
Electrical Phenomena ..

121
Electricity by Simple Contact

369, 422, 423
, Atmospheric

152, 246, 277, 322, 76, 119

Page.
Electricity by Evaporation, Historical Sketch of

117, 353
on the Heat Produced by

287
Perforation of Glass by

327
Electrised Bodies, on the Recession of

1
Electro-Metallurgy

239
Electro-Magnetic Apparatus 81, 82, 85, 87, 255, 337, 416
Electro-Gasometer

495
Electro-Magnetism a Moving Power

496
Electrometer, Dr. Hare's Single Leafed

426
Electro-Gilding

125, 216, 333, 131
Elementary Lectures on Electricity, &c. 173, 250, 330, 500
Elias, Mr., on Electro-Magnetism as a Motive Power

496
Elkington, Messrs., on Electro-Gilding, &c.

131, 125
Espy, James P., Esq., A.M., on the Diurnal Fluctuations of
the Barometer

209
Ethule and Ether

406
Evaporative Power of Steam Boilers

58, 161
Experiments, Voltaic

211
on Electricity from Evaporation

354, 360
on the production of Electricity by Contact 422, 423

F.
Fechner, M.,

23
Franklin, Dr. Benjamin, on Electricity by Evaporation

179, 184
Feremy, M. Edward, on the Action of Alkaline Peroxides on
Metallic Oxides

454

G.
Galvani, Professor

363, 364, 365
Galvanic Pile, on the Activity of

378
Galvanism, on the Theory of

30
Galvanoplastik, Professor Jacobi's

66, 168
Glaisher, Mr., Magnetic Observations

112
Gregory, Dr. Olinthus

341
Griffin, Charles, Esq., on the Recession of Electrised Bodies 1
Grove's Battery, Experiments with

211
Gruil, C. A., on the Construction of Grove's Voltaic Pile
Gymnotus Electricus, Death of one at the Adelaide Gallery 336

75

H.
Hammon, M., on Electro-Gilding
Hare, Dr. Robert

his Experiments with Volta's Plates

his Single Gold Leaf Electrometer
Hare, Clark, Esq., on Ethule and Ether
Harris, W. S., Esq., F.R.S., on a Mariner's Compass
Hauy, L'Abbe, on Electricity by Evaporation

219
337
425
426
406

237
354, 360