376 Dr. L. Bleekrode on the Electric Conductivity 



not needing any high pressure to liquefy them, were enclosed 

 in short straight tubes ; so that small quantities sufficed. The 

 conductivity of the electrolyzed substances was estimated from^ 

 the deflections of the needle of a galvanometer the coil of which 

 was of thin wire, and in which the current from a couple of 

 wires, zinc and silver, immersed in distilled water gave a de- 

 flection of 5°, and of two silver wires in water, which were 

 inserted in the circuit, a deflection of 2°. The current for 

 the experiments on electrolysis was generated by: — first, a 

 galvanic battery of twenty large Bunsen-Deleuil elements ; 

 secondly, a battery of forty elements, which liberated in the 

 voltameter 600 cubic centims. of oxy hydrogen gas per minute; 

 and, thirdly, a battery of eighty elements, which produced 

 840 cubic centims. per minute. Other series of experiments 

 were made with induction-currents : for these I used a Ruhm- 

 korff's induction-coil with a spark-length of 15 millims., and 

 a second, the spark of which attained a length 42-70 millims. 



No currents of such intensity have, to my knowledge, been 

 employed for electrolytic purposes, especially with the sub- 

 stances investigated by me, except in the experiments of 

 Lapschin and Tichanowitsch *. Warren De la Rue's chloride- 

 of-silver battery furnishes currents of far greater intensity ; 

 my experiments with it shall be discussed in a separate section. 



The current was led through the liquid and at the same time 

 through the galvanometer ; but it might be questioned whether 

 the deflection was not conditioned by conduction of the cur- 

 rent in the glass tube | ; and by a metallic, not an electrolytic 

 conduction. In order to determine what was the amount (if 

 any) of conduction along the glass, if the galvanometer showed 

 only a slight deflection, the liquid was removed from between 

 the electrodes by inverting the tube ; the circuit could then be 

 closed only by the glass sides. The deflection now produced 

 I have named the glass-conduction. As, with the exception 

 of alloys, no experiments had shown that compound substances 

 conduct in metallic fashion only, and not at the same time 

 electrolytically, I thought I could infer from the deflection of 

 the galvanometer, not only the conductivity of the compound, 

 but also its liability to electrolysis, although for the most part 

 I could not observe any polarization-current. 



2. Electrolysis of Water. 



All the experiments which have been made, and especially 

 the more recent observations of Kohlrausch, prove that water 



* Bull, de VAcad. de St. Petersb. vol. iv. 1861; Phil. Mag. [IV.] 

 vol. xxii. p. 308. 



t Coiif. Beetz, Pogg. Ann. vol. xcii. p. 465. 



