EXPERIMENTS 1n MAGNETISM. 179 
either afford you fome amufement, or induce you to pur- 
fue the fubje&t to more certainty. 
I duppofe then, that magnetical particles of matter are 
a neceflary conftituent part of that metal which we call 
iron, though they are probably but a {mall proportion of 
the whole mafs. Thefe magnetical particles I fuppofe 
have each a north anda fouth pole, and that they retain 
their polarity, however the metal may be fufed or other- 
wife wrought. Ina piece of iron which fhews no figns of 
magnetifm thefe magnetical particles lie irregularly, with 
their poles pointing in all poffible direGlions, they there- 
fore mutually deftroy each other’s effects. By giving 
magnetifm to a piece of iron we do nothing more than 
arrange thefe particles, and when this is done it depends 
on the temper and fituation of the iron whether that ar- 
rangement fhall continue, that is, whether the piece of 
metal fhall remain for a long time magnetical or not. 
There is fome power, whencefoever derived, diffufed 
through every part of {pace which we have accefs to, 
which aéts on thefe magnetical particles, impelling one of 
their poles in a certain direction with refpect to the earth 
and the other pole in the oppolite direction. The direc- 
tion in which this power acts I take to be the fame with 
that of the dipping needle. 
By applying a magnet toa piece of iron it becomes 
magnetical; for the magnet acting ftrongly on the above 
mentioned particles, that action arranges them properly; 
overcoming the refiftance of the furrounding parts of the 
iron, and this refiftance afterwards ferves to fecure them in 
their proper fituations, and prevents their being deranged 
by any little accident. 
If we place a piece of iron in or near the direction of 
the dipping needle, it will in time become magnetical; 
that general power producing in this cafe the fame effect 
as the application of the magnet, though in a weaker 
degree. 
Tron 
