44 FJcctfO" Magnetic Experimenls, 



Royal Academy of Sciences, on the mutual actions of the earth, 

 the conjunctive wires of a Voltaic apparatus, and a magnetic 

 needle. He presented in the following sittings three new ar- 

 rangements of apparatus, of his invention. The first shows a 

 circular conjunctive wire submitted to the action of a Voltaic ap- 

 paratus, and which is directed by the action of tlie terrestrial 

 globe in a vertical plane, perpendicular to the plane of the mag- 

 netic meridian. The second apparatus consists in a circuit almost 

 closed, and of a rectangular form, which turns round a horizon- 

 tal axis perpendicular to the plane of tiie magnetic meridian, and 

 the plane of which inclines to take, by the action of the earth, a 

 direction perpendicular to that of the inclination of the needle. 

 This inclination, which has not l)een measured with exactness 

 for some years past, was at Paris on tlie 22d April 1819, 68° 25'. 

 It is variable, like the declination, according to times and places. 

 The third apparatus of M. Ampere exhibits a conjunctive wire 

 twisted spirally, the extremities of which are attracted and re- 

 pelled by a magnetic liar, as those of a needle would be. 



The coexistence of the electric and magnetic actions has na- 

 turally led to the idea, that wires submitted to the influence of 

 the terrestrial globe, or of a magnetic needle, may decompose 

 water, like those which communicate with the extremities of a 

 Voltaic pile. 



The following is the account of Professor CErsted's experi- 

 ments : — 



New Electro-Magnetic Experimerits. By Prof. CErsted. 



Subsequently to the first experinjcnts which 1 published on the 

 magnetic action of the galvanic battery, I have extended my re- 

 searches on the sulject as much as various other avocations would 

 allow me. 



The intensity of the electricity seems to have no share in the 

 magnetic effects; they depend solely on its quantity. The dis- 

 charge of a strong electric battery, sent through a metallic wire, 

 produced no change in the position of the magnetic needle. The 

 needle is acted upon by an interrupted snccession of electric sparks 

 through the medium of the ordinary electric attractions and re- 

 pulsions, but no electro-magnetic effect was produced, as far as 

 could be peiceived. In like manner a galvanic pile, consisting of 

 100 discs, each two inches square, and of paper moistened in 

 salt water, to serve as a conductor of the fluid, exhibits no sen- 

 sible effect upon the needle. The effect is, however, produced 

 by a single galvanic arc of zinc and copper, w ith a liquid of pe- 

 culiar conducting power as a conductor; for example, a liquid 

 consisting of one ])art sulphuric acid, an equal part of nitric acid, 

 and sixty parts of water. The quantity of water may even be 



doubled. 



