Magnetism on Chemical Jction. 253 



therefore the more important to settle it with certainty, either 

 one way or the other, if possible. 



It is only honest that I should state, that the results of all 

 my earlier experiments led me to believe that magnetism ex- 

 erted a retarding influence upon chemical action; and under 

 this impression, having made some hundreds of experiments, 

 I submitted a communication to the Royal Society, which I 

 afterwards withdrew, from the circumstance that under some 

 new modifications of these experiments I obtained many ex- 

 ceedingly contradictory results. 



It may be imagined that careless manipulation, or the inter- 

 ference of other influences which should have been guarded 

 against, must have been the cause of this want of uniformity. 

 I am unwilling to admit this ; and although I feel confident 

 that I have esmblished clearly, in some recent experiments, 

 the fact that magnetism exerts no injluence on the chemical 

 action set up, I can only explain the very decided results 

 which crowd the pages of my note-book, and which deceived 

 such men as Hansteen, Fresnel and Ampere, on the sup- 

 position that there exists some molecular forces with which 

 we are not yet acquainted, but which are most sensibly af- 

 fected by several of the elementary forces, and consequently 

 determine the intensity of chemical excitement. In no other 

 way will the phaenomena admit of explanation, which I have 

 again and again witnessed, when iron wires were placed in 

 solutions of litmus, of sulphate of copper, of sulphuric acid, 

 &c., and arranged in different orders in reference to the mag- 

 netic equator, or disposed in various relations as regards 

 powerlid permanent magnets and electro-magnets. 



I do not deem it advisable to occupy the pages of the Phi- 

 losojobical Magazine with any description of these experiments 

 at the present time, particularly, as I intend to pursue the in- 

 vestigation in the hope of elucidating its involved pliocnomena. 

 I desire only to call attention to a form of experiment, which 

 appears to me to be most unobjectionable, and which I think 

 we may legard as an expcrimciifum crncis. 



The conditions which I thought essential to the accurate 

 solution of this (jucstion were the following: — 



1. A correct measure of the amount of chemical action. 



2. Means of tletcrmining if the action was constant and 

 unvarying. 



3. The power of l)ringing the whole under magnetic influ- 

 ence without in any way disturbing the arrangement, or bring- 

 ing any other forces besides magnetism into action. 



This was elFected in the following manner : — A soft iron 

 wire (a), which previously to the experiment was ascertained 



