426 Prof. E. Wartmann's Eighth Memoir on Induction. 



as themselves, and each resting on one of the poles of the 

 magnet. The induction was again without influence. 



223. The experiment was repeated with a bar of bismuth- 

 antimony. Two polar armatures concentrated the maximum 

 of magnetic energy upon the solder, when the cylinder was 

 perpendicular to the axis of magnetization. This heteroge- 

 neous conductor was traversed by the current of the pair in 

 directions successively opposite ; the position of the magnetic 

 poles was also changed. In spite of these alternatives, the 

 absolute value of the deviation of the galvanometer remained 

 invariable. 



224. I wished to anticipate the objection that the electric 

 current passed through my different conductors was too weak 

 not to be admitted without modification, whatever were the 

 molecular changes caused by an intense magnetism, and those 

 which depended on the cessation of that force. I therefore 

 replaced the small cell (218.) by three Daniell's cells of large 

 dimensions, charged with some concentrated sulphate of cop- 

 per and strongly acidulated water. For the liuhmkorff's 

 rheometer I substituted one of Gourjon, No. 27, the wire of 

 which is much longer. A rheostat was connected with this 

 instrument, and the derivation of the rheometer current was 

 effected as has been stated (215). 



225. The repetition of all the preceding experiments led 

 to the same conclusion as before. 



226. A bismuth-iron cylinder was placed first axialiy, then 

 equatoriall}'. The direction of the magnetization was succes- 

 sively deranged. Some armatures magnetized the solder in 

 the diamagnetic position with extreme energy. The result 

 did not vary. 



227. Lastly, I tried the experiment on different liquids, as 

 the chlorides of nickel and cobalt dissolved in distilled water, 

 and on acid solutions of nitrate of bismuth and chloride of 

 antimony. These solutions were contained in glass tubes 

 closed by stoppers which admitted the passage of metallic 

 wires. Here ajjain the rheometric deviation was not at all 

 affected by the induction of the magnet. 



228. It remained to examine the case of a current still more 

 intense, traversing the magnetized conductor. I employed 

 that of a battery of ten large Daniell's elements. But in order 

 not to take measures on too small a portion of the active elec- 

 tricit}', the multiplier was replaced by a voltameter with very 

 large plates of platina. 



229. The armature of the electro-magnet, placed in the 

 circuit, did not vary in conductibility, in whatever direction it 

 was magnetized or brought to its ordinary state. 



