322 Prof' Oersted on Electro-magnetism. [Nov. 



new views are rarely developed even to their authors with perfect 

 clearness. A thorough conviction of the agreement of my 

 theory with facts, inspired me, nevertheless, with so strong a 

 persuasion of its truth, that upon this basis I ventured to form 

 my theory of heat and light, and to attribute to these forces, 

 apparently destroyed, a radiating action capable of penetrat- 

 ing to the greatest distances.^ Having for a long time con- 

 sidered* the powers which are developed by electricity as the 

 general powers of nature, it necessarily followed that I should 

 derive magnetic effects from them.f 



In order to prove that I admitted this consequence to the 

 utmost extent, I cite the following passage from my Researches 

 into the Identity of Electrical and Chemical Powers, printed at 

 Paris inl 8 13, "it must be determined whether electricity in its most 

 latent state has any action upon the magnet as such."$ I wrote 

 this during a journey, so that I could not easily perform the 

 experiments, besides which, the manner of making them was 

 not at that time at all clear to me, all my attention being directed 

 to the development of a system of chemistry. I still remember 

 that I expected, though somewhat vaguely, the effect in question, 

 and particularly by the discharge of a strong electrical battery, 

 and also that I did not hope to obtain more than a weak mag- 

 netic effect. Thus I did not follow the idea which I had con- 

 ceived with the requisite zeal, but the lectures which I delivered 

 upon electricity, galvanism, and magnetism, during the year 

 1820, recalled it. My auditory consisted mostly of persons 

 previously well acquainted with the science. On this account, 

 these lectures and preparatory reflections, led me on to 

 deeper researches than those which are admissible in common 

 lectures. 



My original persuasion of the identity of electric and magnetic 

 powers were developed with greater clearness ; and I resolved to 

 submit my opinion to the test of experiment, and the prepara- 

 tions for it were made on a day in the evening of which I had to 

 deliver a lecture. I there showed Canton's experiment on the 

 influence of chemical a°encv on the magnetic state of iron. I 

 requested attention to the variations of the magnet during a 

 storm, and I mentioned at the same time the conjecture, that an 

 electrical discharge might produce some effect upon the magne- 

 tic needle placed out of the galvanic circuit. I immediately 

 resolved to make the experiment. As I expected the greatest 

 effect from a discharge producing ignition, I inserted at the 

 place under which the needle was situated, a very fine platina 

 wire between the connecting wires. Although the effect was 

 unquestionable, it appeared to me nevertheless so confused that 



* See the letter added to my German publication, Materielen muner Chemie, &c. 

 1803; and also Researches into the Identity of Electrical and Chemical Forces, p. 

 127, &c. 



•J- Letter, p. 234—238. t Letter, p. 238. 



