324 EXPERIMENTS upon MAGNETISM. 



men have fuppofed, that the arrangement of the filings 

 clearly indicated the paflage of a magnetic fluid or effluvia, 

 in curved lines, from one pole to another of a different 

 denomination ; and hence, have fought for the folution 

 of other phenomena upon a much more extended fcale. 

 Others, and particularly Cavallo, in his ufeful treatife on 

 magnetifm, from the adtion of the magnet upon the filings, 

 rendering each particle itfelf a magnet. The proper folur- 

 tion fprings from the foUoMring experiments : 



EXPERIMENT i. 



Place an artificial magnet, of the ufual oblong form, 

 and of fufficient ftrength, upon a difh j let the ends be 

 two or more iaches diftance from the edge or rim ; cover 

 the magnet with water about one-tenth of an inch. Then' 

 fprinkle, or fift the filings of iron through gauze, fo that 

 they may fall gently near the equator of the magnet. 

 You will immediately fee the filings to divide ; one part 

 moving with an accelerated velocity to the north pole ; the 

 other part, to the fouth pole ; each approaching as near to 

 its refpedtive pole, as the interpofing fluid will permit ; 

 each turning and prefenting a diffimilar pole to that which 

 firft put the panicle in motion. As other particles fucceed 

 in their turn, the fame effects take place ; each endeavours 

 to approach as near to its pole, as its centre, as poflTible ; 

 but the particles already arrived, preventing an approach 

 within the limits thus previoufly occupied, the whole are 

 necefllarily arranged in the form of concentric circles. Par- 

 ticles of water in forming drops, or of mercury in form- 

 ing globules, obey nearly the fame law. 



Thus doth this experiment unequivocally demonfirate-, 

 from the motions of the floating particles, that attradlion 

 is the fole caufe of this phenomenon, and that this force 

 ip equally e;certed by each pole. It fhews, at the fame 



timci, 



