the Laws of Magnetic Forces. 319 



pose, that the magnetic distribution in an artificial magnet, the 

 intensity of which increases in a direct ratio of the square of the 

 distance from the centre, is still to be resolved into two simple 

 actions, which may possibly be discovered by a little reflection 

 on the manner of producing magnetic disturbance in bars of 

 steel, and the laws according to which the opposite magnetic 

 forces operate on each other. 



54. Without stopping to inquire into the nature of the cause 

 of magnetic phenomena, we shall only assume what is, in fact, evi- 

 dent by the most simple experiments, that in every magnet there 

 are two opposite forces developed, whether we suppose them to 

 be merely different states of the same principle, or whether we 

 imagine them to be separate and distinct agents. These forces 

 are observed to neutralize each other when united, and to exert 

 more or less of free action as they become separated. 



Some considerations concerning this free action have been al- 

 ready entered upon (30) ; but it will be requisite here to deter- 

 mine the free action developed, by separating the two opposite 

 magnetic forces ; the original magnetic intensities and the dis- 

 tances being both variable. For this purpose, two masses of 

 iron be, da', Fig. 19, 2 inches in length, 0.75 of an inch wide, and 

 0.3 of an inch thick, were placed under the influence of the dis- 

 similar poles of two magnetic bars N, N', so as to induce in them 

 the same magnetic intensities, as measured by the attractive 

 force on the suspended iron <r, in the way before explained (36), 

 by bringing the opposite polarities c and d of the induced mag- 

 nets in contact, their free action would be reduced to zero ; 

 whilst, by withdrawing them from each other, we could estimate 

 the force of the free action in either of them ; 1 when the in- 

 duced magnetic force was a constant quantity, and the distance 

 cd variable, the distance a b, a'b' from the original magnets being 

 the same ; 2 when the distance cd was a constant quantity, but 



