MAQNKT1SM. 93 



evidences of it everywhere. In tho fibre of trees, in grass and 

 In dissolving a piece of iron in acid, it is eaten away 

 in lines. If the frost leaveB on our windows are observed 

 forming on a winter's morning, we may also perceive that 

 tin- fiv>- is in .straight lines, unless they are swayed either one 

 way or other by the polarity of rival shoots. Thus we have Been 

 two fronds starting from the bottom of a sash, a little apart from 

 each other, and shooting out towards the centre, but on the 

 points approaching they each repelled the other, which caused 

 both to curve outward again. 



On breaking a piece of shell ice, we have often seen on the 

 under side, long lines of small spears of ice, formed as regularly 

 the one behind the other, as a regiment on parade. Tyndal! 

 thinks that these magnetic curves will, by the progress of sciencej 

 be found to represent a condition of the " luminiferous ether" 

 which is " the mysterious substratum of all radiant action." 

 We are only sorry for him that these curves will, in the progress 

 of science, only prove that his theories of light and heat are all 

 wrong. 



To resume our facts regarding magnetism, particles of iron 

 are attracted to both ends or poles of magnets, but not to their 

 middle portion or centre. A steel magnet when bent to the 

 of a U, or of a " horse shoe," shows its greatest force at 

 either end, gradually diminishing towards the middle. This 

 may be seen by placing the magnet in iron filings, when the 

 ends by attracting the filings, are united, forming an arch of 

 filings. A piece of soft iron similar in si/e to the ends of the 

 magnet, if brought into contact with the ends, will be imme- 

 diately attracted to the magnet. In this .situation no filings 

 will be attracted to the magnet, because tho ends or poles of 



