

ANNALS 



or 



PHILOSOPHY. 



JANUARY, 1822, 



Article I. 



Further Researches on the Magnetic Phenomena produced by 

 Electricity ; with some new Experiments on the Properties of 

 Electrified Bodies in their Relations to conducting Powers and 

 Temperature.^ By Sir Humphry Davy, Bart. PRS. 



I. In my letter to Dr. WoUaston on the new facts discovered 

 by M. Oersted, which the Society has done me the honour to 

 publish, I mentioned, that I was not able to render a bar of steel 

 magnetic by transmitting the electrical discharge across it 

 through a tube filled with sulphuric acid ; and I have hkewise 

 mentioned, that the electrical discharge passed across a piece of 

 steel through air, rendered it less magnetic than when passed 

 through a metallic wire ; and I attributed the first circumstance 

 to the sulphuric acid being too bad a conductor to transmit a 

 sufficient quantity of electricity for the effect ; and the second, 

 to the electricity passing through air in a more diffused state than 

 through metals. 



To gain some distinct knowledge on the relations of the dif- 

 ferent conductors to the magnetism produced by electricity, I 

 instituted a series of experiments, which led to very decisive 

 results, and confirmed my first views. 



II. I found that the magnetic phgenomena were precisely the 

 same, whether the electricity was small in quantity, and passing 

 through good conductors of considerable magnitude ; or, whe- 

 ther the conductors were so imperfect as to convey only a small 



* From the Philosophical Transactions, for 1821, PartIL 



New Series, vol. in. b 



