70 W. A, Norton on Molecular Physics. 
the circular current. For the same distance the resultant will 
nal ee force of the magnet, 
abed, fig. 10, be a magnet, and let us 
regard its effective action upon any mole- 
cule, at f, as the result of the joint action 
of two sets of opposing currents, the one 
lying in the upper face ad, and the ese 
in the lower —— ed. Let nf=y, n 
i 2 
nr’ =z', nb=u, na=v, ac=d, and mssebetiicion? of the impulsive _ 
force of an indi vidual current, Then for the es of r upon fwe 
md, mdz 
have at and for the action of nr, Rhee be “ tang 20 
a ae entire action of nb, we have the definite integral 
2 
u 
— “tang : In a similar manner we obtain, for the opposing 
action of "eh i tang —_. The effective impulsive action — | 
of the portion nodb of the magnet, — then be 
1 
ca aD mbes thine 
Sy y+a 7 ya" 
The effective Bis of the ad portion, bath of the magnet, 
will be = tang tang 
: y oe 
We therefore have, for és entire wntns - the magnet, 
w ="( tmg - tang“) = ak tang ing 75), 
or, v5 (us 1) Mwcefa) 2. a 
' When y is large as ae with d, we have ce 
w= "(are afe-+-arcbfd) . ge oN (b.) 
~ “To obtain the siti, "Then curve of as vs parabens — 
let mn =a, se ees: en nr=z=2+ 
(tang E*-ttang 8, Alou ts Sint la—gz =\=¢ Ae 
