192 M. W. Beetz on the power of conducting Electncity 



Faraday * bas shown that liquid sulphur and phosphorus do not 

 conduct; hence the statement of J. Inglisf that iodine conducts 

 when fused is quite unexpected. In this case the substance to 

 be tested was contained in a glass tube sealed at both ends, into 

 which two platinum wires were conducted. Solly J contradicted 

 this experiment : he could neither detect the slightest trace by 

 Wollaston's method (in which the body to be investigated is in- 

 troduced into a circuit, both of whose extremities consist of dif- 

 ferent metals which can be placed on the tongue), nor could he 

 observe any decomposition in a solution of iodide of potassium, 

 by means of a battery of 60 elements, when the circuit was in- 

 terrupted by a stratum of melted iodine ^^^th of an inch thick. 



Notwithstanding this, Palmieri §, relying upon the experiments 

 of Inglis, and without mentioning those of Solly, has lately con- 

 structed batteries from three elementary bodies, e. g, from two 

 metals and iodine, wherein the latter takes the place of the elec- 

 trolyte. If the statement concerning the iodine battery was not 

 so simple as to preclude the possibility of error, I should pay no 

 regard to this investigation, seeing that the same physicist con- 

 structs a battery equally well from three metals, one of which is 

 mercury, whose action can evidently be ascribed to no other 

 cause than to the moisture adhering to the mercury. A glass 

 ilask which contained somewhat more than one ounce of iodine 

 was closed with a cork, the iodine was then fused, and air ad- 

 mitted several times during the process by removing the cork, 

 after which two plates of platinum and iron, connected with a 

 delicate galvanometer, were immersed in the liquid mass. The 

 galvanometer at once announced a current traversing the wire 

 from the platinum to the iron. No perceptible residue was at 

 first obtained when the iodine which had been used was evapo- 

 rated on a platinum plate ; after repeating the experiment several 

 times a small residue containing traces of iron was obtained. 

 The action was still stronger when iodine was fused in a platinum 

 crucible and an iron plate dipped into it, the crucible and plate 

 being both connected with the galvanometer. 



In order first to come to a decision as to the fact of the con- 

 ducting power of liquid iodine, I made the following experiment. 

 Two platinum wires connected with a galvanometer were im- 

 mersed in a porcelain dish containing iodine, and the dish heated. 

 As the iodine began to fuse, a deviation of the astatic system, 

 amounting to about 15°, was observed; when the wires were 

 immersed after the iodine had been fused, the deviation was 



* Experimental Researches, par. 405. 



t Biol. Univ. de Gen. Nouv. ser. 1. p. 167; Phil. Mag. S. 3. vol. vii. p. 441. 

 J Ann.de Chim.et deFhys. vol. xxxv.p.160; Fogg. ylnw. vol.x.p.307. 

 § Rendic. delta R. Ace. de Nap. vol. ix. p. 161. 



