"Primary Laws. S3 



Third Proposition. — -Atoms, molecules, and aggregates 

 of molecules issuing from the same pole of a magnet 

 become suffused with the same polarity. Hence, as like 

 poles repel one another, a mutual repulsion is manifested 

 by the charged material, which results in the isolation 

 of filaments, stalks, tzoigs, and branches, all repelling 

 one another. 



The facts illustrative of this law are as follows : — 

 If a number of needles be attached by their heads 

 to the pole of a magnet, all their points repel one 

 another, for each needle becomes magnetised, and 

 acquires at its point similar polarity to the pole of the 

 magnet. The magnet, in fact, is only lengthened. 

 Hence, as like poles repel, all the needle points repel 

 one another. Again, if the end of a magnet be dipped 

 in filings, the bunch thereby attracted and magnetised 

 becomes a bristling mop of mutually repellant fila- 

 ments. Each minute filing also, could we test it, 

 would prove a complete magnet with two poles 

 systematically arranged, each adhering to the other 

 by opposite poles. 



Another beautiful experiment is as follows : — 

 Lay a flat bar-magnet on a plate of glass, sprinkle 

 over it some iron filings, tap the glass, and if the 

 experiment be carefully performed, the filings at both 

 ends will automatically fall into lines, each line widen- 

 ing as its distance from its own pole increases; the 

 diverging force, as in the previous experiment, being 

 like-polar-repulsion. But the filings do not continue 

 to radiate in straight lines from the poles to infinity ; 



