ELECTRICAL UNITS OF MEASUREMENT. 81 



the same thing was done for electro-magnetism 

 by Ampere. 



I speak of electricity, of magnetism, and of 

 electro-magnetism. Now I must premise, as a 

 matter of importance in respect of some of the 

 technical details which we shall have to con- 

 sider later, that magnetism must be held to 

 include electro-magnetism, Electro-magnetism 

 and magnetism are one and the same thing. 

 Electro-magnetic and electro-static force, which 

 are very distinct just now, are two things which 

 deeper science may lead us to unite, in a manner 

 that we can scarcely see at present. We have 

 the foundation of Cavendish for electricity, of 

 Coulomb, for magnetism, and of Ampere for 

 electro-magnetism, which fall in perfectly with 

 what I shall have to say later on, in respect of 

 Gauss and Weber's work, of magnetism and electro- 

 magnetism. I say this, because there has been 

 some little discussion in respect to the magnetic 

 unit and the electro-magnetic unit, as if the 

 magnetic unit might be something different 

 from the electro-magnetic unit, or the electro- 



G 



