374 FRAGMENTS OF SCIENCE 



by their separation we could produce the duality of action 

 of magnetized bodies. 



But you have already anticipated a defect in my con- 

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

 middle we have one half entirely red, and the other en- 

 tirely 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 sup- 

 pose each molecule of the wood painted green on one face 

 and red on the opposite one. The resultant action of all 

 the atoms would then 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. 



For these two self-repellent and mutually attractive 

 colors substitute in your minds two invisible self-repel- 

 lent 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, plac- 

 ing the opposite fluids on the opposite face of each mole- 

 cule. You have then 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. Accord- 

 ing to this theory nothing is actually transferred from the 

 exciting magnet to the excited steel. The act of mag- 

 netization consists in the forcible separation of two fluids 

 which existed in the steel before it was magnetized, but 

 which then neutralized each other by their coalescence. 

 And if you test your magnet, after it has excited a hun- 

 dred pieces of steel, you will find that it has lost no force 

 —no more, indeed, than I should lose, had my words such 



