A HISTORY OF SCIENCE 



the three together seemed hardly to weaken the effect, 

 and the same was the case with an earthen vessel, even 

 when it was full of water. Our experiments also de- 

 monstrated that the said effects were not altered when 

 we used a magnetic needle which was in a brass case 

 full of water. 



" When the conductor is placed in a horizontal plane 

 under the magnetic needle all the effects we have de- 

 scribed take place in precisely the same way, but in 

 the opposite direction to what took place when the 

 conductor was in a horizontal plane above the needle. 



" If the conductor is moved in a horizontal plane so 

 that it gradually makes ever-increasing angles with the 

 magnetic meridian, the deviation of the magnetic 

 needle from the magnetic meridian is increased when 

 the wire is turned towards the place of the needle; it 

 decreases, on the other hand, when it is turned away 

 from that place. 



" A needle of brass which is hung in the same way as 

 the magnetic needle is not set in motion by the influ- 

 ence of the conductor. A needle of glass or rubber like- 

 wise remains static under similar experiments. Hence 

 the electrical conductor affects only the magnetic 

 parts of a substance. That the electrical current is 

 not confined to the conducting wire, but is compara- 

 tively widely diffused in the surrounding space, is 

 sufficiently demonstrated from the foregoing obser- 

 vations." 2 



The effect of Oersted's demonstration is almost in- 

 comprehensible. By it was shown the close relation- 

 ship between magnetism and electricity. It showed 



238 



