ELEMENTAEY MAGNETISM. 347 



give you a suspending fibre void of torsion. Make a 

 little loop of paper, or of wire, and attach your fibre 

 to it. Do it neatly. In the loop place a darning- 

 needle, and bring the two ends or poles, as they are 

 called, of your bar-magnet successively up to the ends 

 of the needle. Both the poles, you find, attract both 

 ends of the needle. Replace the needle by a bit of 

 annealed iron wire ; the same effects ensue. Suspend 

 successively little rods of lead, copper, silver, brass, 

 wood, glass, ivory, or whalebone ; the magnet produces 

 no sensible effect upon any of the substances. You 

 thence infer a special property in the case of steel and 

 iron. Multiply your experiments, however, and you 

 will find that some other substances, besides iron and 

 steel, are acted upon by your magnet. A rod of the 

 metal nickel, or of the metal cobalt, from which the 

 blue colour used by painters is derived, exhibits 

 powers similar to those observed with the iron and steel. 

 In studying the character of the force you may, 

 however, confine yourself to iron and steel, which are 

 always at hand. Make your experiments with the 

 darning-needle over and over again ; operate on both 

 ends of the needle ; 'try both ends of the magnet. Do 

 not think the work dull ; you are conversing with 

 Nature, and must acquire over her language a certain 

 grace and mastery, which practice can alone impart. 

 Let every movement be made with care, and avoid 

 slovenliness from the outset. Experiment, as I have 

 said, is the language by which we address Nature, and 

 through which she sends her replies ; in the use of this 

 language a lack of straightforwardness is as possible, 

 and as prejudicial, as in the spoken language of the 

 tongue. If, therefore, you wish to become acquainted 

 with the truth of Nature, you must from the first re- 

 solve to deal with her sincerely. 



