254 INDUCTION OF 



flattened, that is, expands at right angles to the line 

 of motion ; and a solid body, under similar con- 

 ditions, tends to the same result, as evidenced by the 

 fracture it undergoes if the momentum be sufficient. 



This law may perhaps be traced in the production 

 of magnetism from electricity. For a wire, while it 

 conducts, at the same time resists, the electric 

 current, and the iron bar across which it passes pre- 

 sents to it (that is, to a certain proportion of it) a 

 direction of less resistance, at the same time altering 

 its form. But the resistance of the wire tends to 

 turn the electric current at right angles, which is the 

 direction it assumes when it becomes magnetism. 



If the resistance be not absolute (that is, if the 

 motion be only partially turned from its direction, or 

 if, it being entirely turned, the original force con- 

 tinues in operation so that it is constantly renewed), 

 the direction assumed will lie between the original 

 course and a line at right angles to it. 



And if the force producing the motion and the 

 resistance are both of continued operation, the 

 resulting motion will be curvilinear. One illus- 

 tration will suffice. A bubble rising rapidly through 



