Researches in the Theory and Calculus of Operations. 291 



forms a mass of fixed atomic compounds ; and when the 

 mass is further prepared, and the magnetical movement 

 initiated by the methods of touch, etc., the action persists 

 by virtue of the principle of the immanent genesis of force 

 (coercitive force, Poisson). 



27. In a magnetic needle (fig. 23), the electrical currents 

 circulate dextrorsely from the north pole; and an electric 

 current following in a linear direction tends to bring a 

 neighboring current into parallelism. The current moving 

 in the wire from A to A', if the needle be freely suspended 

 over the wire (above the plane of the paper), parallel to the 

 wire, north pole towards A and south pole towards A 7 , it 

 will take the perpendicular (equatorial) position £TS, because 

 in this position its circular current approaches to parallel- 

 ism with the current in the wire (CErsted). 



The analogy between the magnet and a solenoid is too 

 palpable to need remark. The circulo-spiral or helicoidal 

 rotation is in force in the solenoid, but there is no transla- 

 tory movement; while in the real magnet, the opposing 

 spherical emanations render the linear tendency astatic. 

 In the solenoid (fig. 20), there is helicoidal, but no linear 

 movement proper; in the magnet M, there is the same spiro- 

 neliacal or helicoidafcmovement, and also linear movements 

 (of force) from the centre C in the opposite directions Ca 

 and Ca', which destroy each other. We see then why the 

 solenoid and magnet place themselves perpendicularly to 

 the current in the electric wire. 



At A (fig. 25) is an advancing train of electrical atoms, 

 colliding with the stationary train A' at the point : the 

 open half of the spheres represents the force destroyed by 

 the collision, the shaded halves representing the liberated 

 portions which effectuate the successive destructions from 

 centre to centre through the line. From the centre of col- 

 lision 0, the propagation is positive from to A', nega- 

 tive from to A, evidencing the direct and reverse course 



