1821.] 



British Legislation. 



71 



bring the other into a bituation where it may 

 be parallel to it, and in the same direction. 



3. These attractions and repulsions an* 

 absolutely different from the attractions and 

 repulsions of ordinary electricity. 



4. All the phenomena discovered by Mr. 

 Oersted, and which I analyzed, and reduced 

 to two general facts in my first memoir, are 

 embraced by the law of the two electrical 

 CHrrents, (§ 1.), admitting that a magnet is 

 only an assemblage of electrical currents, 

 produced by the mutual action of the par- 

 ticles of steel, analogous to that of the ele- 

 ments of a voltaic pile, and wliich move in 

 planes perpendicular to the line which joins 

 the two poles of the magnet. 



5. When the magnet is in the situation 

 which it tends to take by tlie action of the 

 terrestrial magnet, these currents have a 

 direciion opposite to that of the apparent 

 motion of the sun, and hence when we place 

 a magnet in a contrary position, so ihat the 

 poles which point to the poles of the earth 

 are of the same name, the currents will be 

 found in the direction of the apparent mo- 

 tion of the sun. 



6. This law embraces the phenomena of 

 the ordinary action of magnets. 



7. It embraces also the phenomena of 

 terrestrial magnetism, by supposing electrical 

 currents in planes perpendicular to the di- 

 rection of the dipping-needle, and which 

 move from east to west. 



8. There is no difference between the 

 poles of a magnet, than that one of them is 

 found to the left, and the other to the right 

 of the electric currents, which give to steel 

 the magnetic property. 



9. When Volta had proved that the posi- 

 tive and negative electricities of the pile at- 

 tracted and repelled one another, according 

 to the laws of ordinary electricity, he did 

 not demonstrate completely the identity of 

 the two fluids put in action by the pile and by 

 friction ; but it became a physical truth, per- 

 haps, when he shewed that two bodies, one 

 of which was electrified by metallic contact, 

 and the other by friction acted upon one ano- 

 ther in every case, as if they had been both 

 electrified by the pile, or with the ordinary 

 electrical machine, — the same kinds of proof 

 are obtained with respect to the identity of 

 the attractions and repulsions of electric cur- 

 rents and magnets. Magnetic attractions 



and repulsions, therefore, ought not (o be 

 assimilated to those which result from elec- 

 trical tension, but to those which I have ob- 

 served between two currents. 



M. Ampere has communicated in his third 

 Memoir, several very important results. He 

 has succeeded in directing the uniting wire 

 (fil conjouctif) by the action of the earth. 

 Setting out from his method of considering 

 the phenomena presented by the uniting 

 wires of magnets, he concludes, that the 

 moveable part of tlie uniting wire ought to 

 form a curved plane, and almost shut, so 

 thai there remains only between its extremi- 

 ties an interval necessary (oenable ittocom- 

 municate with the pile, and that then the 

 plane of this curve will be carried by the ac^ 

 tiou of tiie terrestial globe in a direction per- 

 pendicular to that of the dipping-needle. 

 This conclusion has been fully confirmed by 

 experiment. 



According to the manner in which he sus- 

 pends this part of the uniting wire, he has 

 obtained the motion in a horizontal direction, 

 which corresponds with the declination of 

 the compass, and a motion in the magnetic 

 meridian corresponding to the dip. 



On the 30th October, 1820, M. BioT pre- 

 sented a Memoir to ihe Academy, on the 

 Physical Laws of the Electro-Magnetic Phe- 

 nomena, which he had deduced from mea- 

 sures of the deviation and the oscillation ex- 

 perienced by needles placed near the uniting 

 wire. 



The following is the general expression 

 which he has given of the action exerted at 

 a distance upon a particle of austral or bo- 

 real magnetism, by a very fine uniting wire 

 of copper, of an indefinite length, and put 

 in communication with the two poles of a 

 voltaic apparatus. 



From the point where the particle resides, 

 draw a perpendicular line to the axis of the 

 wire. The force which acts upon the par- 

 ticle is perpendicular to this line and to the 

 axis of the wire. Its intensity is in the in- 

 verse ratio of the simple distance. The na- 

 ture of its action is the same as that of a 

 magnetic-needle, which is placed tangen- 

 tially to the contour of the wire, so that a 

 particle of austral and a particle of boreal 

 magnetism would be drawn in opposite di- 

 rections, though always in the same straight 

 line determined by the preceding construction. 



BRITISH LEGISLATION. 



ACTS PASSED in the first year of the reign of george the fourth, or in 

 the FIRST SESSION of (he seventh parliament of the united kingdom. 



CAP. XCV. For obtaining Re- 

 turns from Turnpike Road Trusts 

 of the Amount of t/ieir Revenues^ and 

 JSitpence of maintaining the same. — 

 4uly 24, 1S20. 



CAP. XCV I. For defraying, until 

 Ihe Twenty-fifth Day of June, One thou- 

 sand eight hundred and twenty-one, the 

 Charge of the Pay and Clothing of the 



Militia of Ireland ; and for making Al- 

 lowances to Officers and Quarter masters 

 of the said Militia during Peace. — July 

 24, 1820. 



CAP. XCVII. An Act to revive 

 and to continue. For One Year, the 

 several Acts for the Relief of Insolvent 

 Debtors in Ireland.— J n\y 24th, 1820. 



CAP. XCVIII. To amend an Act 

 passed 



