NOMOS. 61 



to form the molecule of sulphate of soda, and then 

 the similar molecules of sulphate of soda seek each 

 other and unite to form the crystals of this salt. We 

 also assume that molecules of very different sub- 

 stances may be similar electrically. Thus, the 

 molecules in different parts of a galvanic circuit are 

 of very different substances, but they are all similar 

 electrically, in that they have all the same binary 

 constitution, with their corresponding elements all 

 turned in the same direction. 



It would seem, therefore, that we may find the 

 physical explanation of the movements of which we 

 have been speaking in common chemical phenomena, 

 or rather in that common law to which the pheno- 

 mena of chemistry and electricity are, in all proba- 

 bility, alike subject. And this is an important 

 point ; for in the simple fact that currents passing in 

 the same direction attract each other, and that cur- 

 rents passing in opposite directions recede from each 

 other, we find the clue to the interpretation of those 

 phenomena of electrical and magnetical motion 

 which have now to be considered. 



In pursuing our inquiry, it is desirable to realize 

 in some degree the nature of that intimate con- 

 nexion which has been shown to exist 



, . . . .. The connex- 



between electricity and magnetism ; and ion between 



, ,1 ' i ,! electricity 



in order to this, we may ponder with a nd magnet- 

 advantage upon the phenomena which are 

 exhibited in a moveable spiral conductor during the 



