6 Ash WORTH, Intrinsic Field of a Magnet. 



and the magnetic work may be written 



Equating the magnetic to the electric work, we have 



\lH^^dq^Edq 



. rj _ 2E I 2E I 



<T being the specific magnetisation. 



3. The magnitude of the intrinsic field is obtained as 

 follows : — 



Iron. 2E 



Zrr 



E- -03 X 10- cg.s units {vide R. Paillot loc. cit.). 

 Z= 3 X io~^ cg.s. units for divalent iron. 



ff= 212. 



2 X o^ X 10* 

 * 3 X io~" X 212 

 = 9"4 X 10" 



According to Prof Weiss'' the maximum intrinsic field 

 of iron is 65 x 10® gausses. 



Nickei. 



E= 'ooi X io''{?) (vide Hurmuzescu /oc. cit.'). 



Z= 3 "08 X 10"* cg.s. units for divalent nickel. 



<r=56. 



2 X 10^ 

 H, - 



3"o8 X 10"^ X 56 



= I'2 X 10^. 



According to Prof Weiss^ the maximum intrinsic field 

 of nickel is 6"4 x 10® gausses. 



The values for E and cr given above are maxima, but 

 the E.M.F. of magnetisation of nickel is not precisely 

 stated, but is said to be of the order given above. 



^ P. Weiss and P. N. Beck,/, dt Phys., 1908, (4), t. vii., p. 249. 



