368 FRAGMENTS OF SCIENCE. 



ception ; for if we break one of our strips of wood in the 

 middle we have one half entirely red and the other entirely 

 green, and with these it would be impossible to imitate the 

 action of our broken magnet. How, then, must we modify 

 our conception? We must evidently suppose each atom 

 of wood painted green on one face and red on the opposite 

 one. If this were done the resultant action of all the atoms 

 would exactly resemble the action of a magnet. Here, also, 

 if the two opposite colors of each atom could be caused 

 to mix so as to produce white, we should have, as before, 

 perfect neutrality. 



Substitute in your minds for these two self-repellant 

 and mutually attractive colors two invisible self-repellant 

 and mutually attractive fluids, which in ordinary steel are 

 mixed to form a neutral compound, but which the act of 

 magnetization separates from each other, placing the oppo- 

 site fluids on the opposite faces of each atom, and you have 

 a perfectly distinct conception of the celebrated theory of 

 magnetic fluids. The strength of the magnetism excited is 

 supposed to be proportional to the quantity of neutral fluid 

 decomposed. According to this theory nothing is actually 

 transferred from the exciting magnet to the excited steel. 

 The act of magnetization consists in the forcible separation 

 of two powers which existed in the steel before it was mag- 

 netized, but which then neutralized each other by their coa- 

 lescence. And if you test your magnet after it has excited 

 a hundred pieces of steel, you will find that it has lost no 

 force — no more, indeed, than I should lose had my w r ords such 

 a magnetic influence on your minds, as to excite in them a 

 strong resolve to study natural philosophy. I should, in 

 fact, be the gainer by my own utterance and by the reac- 

 tion of your strength ; and so also the magnet is the gainer 

 by the reaction of the body which it magnetizes. 



Look now to your excited piece of steel ; figure each 

 atom to your minds with its opposed fluids spread over its 



