264 Prof. E. Wartmann's third Memoir on Induction. 



91. To meet the objection that the influence of the magnet 

 is not sufficiently felt on the lamina of platina, I constructed 

 two new voltameters (Plate V. figs. 1 and 2) in which the 

 electrodes are prisms of soft iron, gilded by the galvanic pro- 

 cess, and which I magnetize by placing them upon the polar 

 surfaces of die large magnet (86), covered with a very thin 

 isolating leaf of mica. In one of these apparatus, the prisms 

 are C^'OSO in breadth. Repeated experiments, made with 

 batteries of variable force, sometimes collecting the two gases, 

 sometimes the hydrogen alone, and decomposing acidulated 

 or alkaline water, have invariably led to the same results. 



92. But, it will be said, the electric current which imparts to 

 the magnet its power, is an uninterrupted current and incapable 

 of exerting any action upon the electrolyte which is not in its 

 circuit. In order to remove this difficulty, I substituted elec- 

 tricity of tension for that of the current. A fourth voltameter 

 (fig. S) was constructed so as to ensure the most perfect isola- 

 tion between its poles. Behind these, against the sides of the 

 glass vessel, I fixed two platina laminae, one-half of which was 

 immersed vertically 0™'03 in the liquid to be decomposed, 

 whilst the ether was continued outside in a horizontal band 

 terminated by a ball. A thick coating of wax on the exte- 

 rior of the voltameter prevented all electric communication 

 between these laminae, except through the liquid. The hydro- 

 gen produced in the unit of time by the electrolysis of the 

 acidulated water was measured carefully. The quantity of 

 gas did not vary when one of the laminag of platina was placed 

 in relation with the conductor of a powerful electrical machine 

 (with a plate three metres in circumference), the other lamina 

 communicating with the ground ; or when these lamina? were 

 employed to connect the armatures of a battery of three 

 large Leydenjars, kept constantly charged. The direction of 

 the analysing current was changed without the effect being 

 modified. 



93. We may conclude from the preceding experiments, that 

 statical or dynamical induction has no injluencc upon the clie- 

 mical actions engendered by electricity. 



§ X. Are magnets capable of producing chemical action ? 



94. The subject which I have alluded to in the preceding 

 paragrapli is so intimately connected with the controverted 

 question of the chemical actions produced by magnets and by 

 terrestrial magnetism, that I deemed it necessary to devote to it 

 some special experiments. Most observers who have studied it 

 have used only magnets of small power. I have employed 

 electro-magnets of great energy, which were at my disposal, to 



