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XXV. On the Conducting Power of Iodine, Bromine, and 
Chlorine for Electricity. By Epwarp Souty, Jun., Esq.* 
QW the Philosophical Magazine and Journal of Science; 
No. 42, p. 441, Dr. Inglis, in his prize essay on iodine, 
states that he has found solid iodine to be a conductor of elec- 
tricity. In my own observations I had always found it a non- 
conductor ; I was therefore led to repeat my experiments with 
greater care, and the following are the results. 
1. I first sought for conducting power by the beautiful me- 
thod proposed by Dr. Wollaston, namely, the effect produced 
upon the tongue when two metals of different degrees of oxi- 
dibility, placed on either side of it, are made to communicate 
with each other, through any portion of conducting matter. 
lodine was melted in a thin glass tube, which, when cold, was 
broken, and the iodine obtained in a solid state ; a portion was 
then placed between the extremities of the two metals; but on 
no occasion was the least taste produced ; though if the metals 
were connected together only by being immersed in spring 
water, a taste was immediately perceived. When the two 
terminations of the metal plates are made to dip into 2 solution 
of iodine in water, a strong taste is perceived. 
2. In order to examine the conducting power with the vol- 
taic battery, and where the application of the tongue would 
have been uncertain and inconvenient, the following apparatus 
was used. BD J K is a slip of glass, on which two pieces 
of bibulous paper, E and F, soaked in a solution of iodide of 
potassium, are placed. The wire A, resting upon E, was al- 
ways made the anode C; or that resting an F, the cathode: 
thus arranged, of course no action. took place. But if a wire 
was made to touch with one end the paper F, and with the 
other end the paper E, the usual series of pheenomena took 
place ; iodine was evolved at A, and also at that end of the tem- 
porary wire which rested upon F. The fluid to be examined 
was placed in a glass tube, G, having two platinum wires, H 
and I, fused into it; they were separated from each other by 
an interval of about the jth of an inch; thus, when the two 
wires were made to rest upon the two pieces of paper F and 
* Communicated by the Author.—It appears that we were correct in 
thinking that Dr. Inglis’s experiments on this subject would attract atten- 
tion. He has favoured us with the following reply to our note respecting 
it appended to the first part of his paper, as referred to above. “In answer 
to the note regarding the conducting power of iodine, I may just quote a 
sentence from my original Essay: ‘The preparation sent in, shows the state 
in which iodine requires to be, for the transmission of Electricity. It has 
merely been fused in a glass tube, and the tube afterwards broken from 
around it. But although it still continues to conduct, it did so with far 
more energy when in the fluid state.’ Dec. 18, 1835.”—Enrr. 
