ELEMENT AH T MA QNETISM. 271 
gainer by my own utterance, and by the reaction of your 
fervor. The magnet also is the gainer by the reaction of 
the body which it magnetizes. 
Look now to your excited piece of steel; figure each 
molecule with its opposed fluids spread over its opposite 
faces. How can this state of tilings be permanent? The 
fluids, by hypothesis, attract each other; what then, keeps 
them apart? Why do they not instantly rush together 
across the equator of the atom, and thus neutralize each 
other? To meet this question philosophers have been 
obliged to infer the existence of a special force, which 
holds the fluids asunder. They call it coercive force', and 
it is found that those kinds of steel which offer most 
resistance to being magnetized which require the greatest 
amount of "coercion" to tear their fluids asunder are the 
very ones which offer the greatest resistance to the reunion 
of the fluids, after they have been once separated. Such 
kinds of steel are most suited to the formation of per- 
manent magnets. It is manifest, indeed, that without 
coercive force a permanent magnet would not be at all 
possible. 
Probably long before this you will have dipped the end 
of your magnet among iron filings, and observed how they 
cling to it; or into a nail-box, and found how it drags the 
nails after it. I know very well that if you are not the 
slaves of routine, you will have by this time done many 
things that I have not told you to do, and thus multiplied 
your experience beyond what I have indicated. You are 
almost sure to have caused a bit of iron to hang from the 
end of your magnet, and you have probably succeeded in 
causing a second bit to attach itself to the first, a third 
to the second; until finally the force has become too feeble 
to bear the weight of more. If you have operated with 
nails, you may have observed that the points and edges 
hold together with the greatest tenacity; and that a bit of 
iron clings more firmly to the corner of your magnet than 
to one of its flat surfaces. In short, you will in all likeli- 
hood have enriched your experience in many ways without 
any special direction from me. 
Well, the magnet attracts the nail, and the nail attracts 
a second one. This proves that the nail in contact with 
the magnet has had the magnetic quality developed in it 
by that contact. If it be withdrawn from the magnet its 
