114 MAGNETISM. 



this subject at present ; you see clearly there 

 are two kinds of electricities which may be 

 obtained by rubbing shellac with flannel or glass 

 with silk. 



Now, there are some curious bodies in nature 

 (of which I have two specimens on the table) 

 which are called magnets or loadstones; ores of 

 iron, of which there is a great deal sent from 

 Sweden. They have the attraction of gravita- 

 tion, and attraction of cohesion, and certain 

 chemical attraction ; but they also have a great 

 attractive power, for this little key is held up 

 by this stone. Now, that is not chemical at- 

 traction, it is not the attraction of chemical 

 affinity, or of aggregation of particles^ or of 

 cohesion, or of electricity (for it will not attract 

 this ball if I bring it near it), but it is a sepa- 

 rate and dual attraction, and what is more, one 

 which is not readily removed from the substance, 

 for it has existed in it for ages and ages in the 

 bowels of the earth. Now we can make arti- 

 ficial magnets (you will see me to-morrow make 

 artificial magnets of extraordinary power). And 

 let us take one of these artificial magnets, and 

 examine it, and see where the power is in the 

 mass, and whether it is a dual power. You see 



