276 Mr. H. M. Noad on the peculiar 



that of a current the relation of cause to effect, or, generally 

 speaking, that voltaic electricity is due to chemical action and 

 by no means to contact. 



I am quite confident that inactive iron can be used in a 

 great number of cases for obtaining results similar to that just 

 spoken of, and that the peculiar state of this metal offers to 

 philosophers in many other respects a most valuable means 

 for making electro-chemical researches. 



Bale, October 1836. 



L V. On the peculiar Voltaic Condition of Iron, 

 By H. M. Noad, Esq, 



To the Editors of the Philosophical Magazine and Journal, 



Gentlemen, 

 nPHE singular phaenomena presented by iron when put 

 -■■ under certain circumstances into nitric acid, which have 

 been so well described in your Magazine by Professor 

 Schoenbein, and for which Dr. Faraday has, with his usual 

 ability, offered an explanation, had such an interest with me 

 that I was induced to repeat all the experiments which have 

 been described in your Journal ; and in the course of these 1 

 was led to make other observations, which if you think worth 

 while I shall feel obliged by having inserted in your next 

 publication. When a wire that was made inactive by platina 

 was dipped into a vessel of nitric acid, sp.gr. 1*374, and con- 

 nected with the galvanometer, and a common iron wire, Jirst 

 connected with the galvanometer, and then dipped into the 

 acid, no action either electrical or chemical took place ; but if 

 it was put into the acid first there was always strong action, 

 and the needle was deflected in the same manner as if the se- 

 cond wire was zinc and the first platina ; action was then ge- 

 nerally communicated for a moment to the first wire, and after- 

 wards both wires were brought to the peculiar state and the 

 needle was of course quiescent: if now either wire was touched 

 in the acid with a common iron or copper wire, it was thrown 

 into action, and the galvanometer was affected, the active wire 

 playing the part of zinc. If instead of an inactive wire in this 

 experiment a piece of platina was used, the moment the cir- 

 cuit was closed and the second wire was in action, bubbles of 

 gas made their appearance on the platina ; and if a common 

 iron wire, round which a small piece of platina foil was wrap- 

 ped, was substituted for the platina wire, these bubbles rose 

 rapidly from all parts of the foil, but not one appeared on the 



