of Flame and Gases, 419 



more than half an inch in diameter. When these poles were 

 in their place, and from 0"3 to 0*4 of an inch apart, a taper 

 flame, burning freely between them, was for a few moments 

 unaffected by throwing the magnet into action; but then it 

 suddenly changed its form, and extending itself axially, threw 

 off' two horizontal tongues, which entered the passages in the 

 poles; and thus it continued as long as the magnetism continued, 

 and no part of it passed equatorially. 



On using a large flame made with the cotton ball and aether, 

 two arms could be thrown off" from the flame by the force of 

 the magnetism, which passed in an equatorial direction, as 

 before; and other two parts entered the passages in the mag- 

 netic poles, and actually issued out occasionally at their further 

 extremities. 



When the poles were about 0*25 of an inch apart, and the 

 smoking taper was placed in the middle between them level 

 with the centres of the passages, the effect was very good ; for 

 the smoke passed axially and issued out at the further ends of 

 the pole passages. 



Coal-gas delivered in the same place also passed axially, 

 /. e. into the pole passages and parallel to the line joining them. 



A little consideration easily leads to the true cause of these 

 effects, and shows that they are not inconsistent with the 

 former results. The law of all these actions is, that if a par- 

 ticle, placed amongst other particles, be morediamagnetic (or 

 less magnetic) than them, and free to move, it will go from 

 strong to weaker places of magnetic action ; also, that particles 

 less diamagnetic will go from weaker to stronger places of 

 action. Now with the poles just described, the line or lines 

 of maximum force, are not coincident with the axis of the 

 holes pierced in the poles, but lie in a circle having a diameter, 

 probably, a little larger than the diameter of the holes; and 

 the lines within that circle will be of lesser power, diminishing 

 in force towards the centre. A hot particle therefore within 

 that circle will be driven inwards, and, being urged by succes- 

 sive portions of matter driven also inwards, will find its way 

 out at the other ends of the passages, and therefore seem to go 

 in an axial direction ; whilst a hot particle outside of that 

 circle of lines of maximum force will be drivenoutwards,and so, 

 with others, will form the two tongues of flame which pass off 

 in the equatorial direction. By bringing the glowing taper to 

 different parts, the circle of lines of maximum magnetic inten- 

 sity can be very beautifully traced ; and by placing the taper 

 inside or outside of that circle, the smoke could be made to pass 

 axially or equatorially at pleasure. 



I arranged an apparatus on this principle for trying the 



2 E2 



