

24 o GENERAL SCIENCE 



several magnets with opposite poles together, suggest 

 that the molecules of which the iron is composed are 

 small magnets. When all the molecules of a steel bar 



are so arranged that 

 the N pole of one 

 molecule is in contact 

 with the S pole of the 



ARRANGEMENT OP MOLECULES IN next molecule, and SO 



UNMAGNETIZED IRON OR STEEL on through the entire 



bar of steel, then all 



the molecules at one end of the bar would have their N 

 poles exposed and the molecules at the other end would 

 have their S poles exposed. By jarring or heating a 

 magnet the molecules are so disturbed that their align- 

 ment is broken and they arrange themselves in groups 

 and short chains until no magnetism is left. When a 

 steel bar is being magnetized, the molecules are being 

 drawn into alignment so that opposite poles of the mole- 

 cules touch one another. If a steel bar is being mag- 

 netized, jarring it while between two poles of a magnet 

 will assist in causing the molecules to take the proper 

 arrangement. Soft iron is easily magnetized, but it 

 does not retain the magnetism like a steel bar. 



165. Induced Mag- 

 netism. - - If a tack 

 or a small nail is sus- 

 pended from the end 



Of a bar magnet, a ARRANGEMENT OP MOLECULES^ 



second tack can be MAGNETIZED IRON OR STEEL 



hung to the first and 



a third to the second, because each tack acts as a magnet 

 and holds the one next below it. If the upper tack is 

 carefully removed from the bar magnet, all the other 



