THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



XLV. The Theory of the Intrinsic Field of a Magnet and 

 the relation of its Magnetic to its characteristic Electric and 

 1 hernial Properties. By J. R. Ashwokth, D.Sc* 



Index to Paragraphs. 



1. The Intrinsic Field of a Magnet — Discussion of the subject. 



2. Resistivity under an alternating field. 



3. Thermo-electric Power under an alternating held. 



4. Specific heat under an alternating Held. 



5. Corresponding States. 



6. Theory of a combined magnetic and molecular intrinsic 



field. 



7. How it accords with the facts of magnetism. 



8. How it accords with the facts of specific heat. 



9. How it accords with the facts of resistivity. 

 10 Recapitulation. 



1. The Intrinsic Field of a Magnet. — The theory of the 

 magnetism of a ferro-magnetic material, which regards the 

 intensity of magnetization as analagous to the density of a 

 fluid and treats it as a function of both field strength and 

 temperature, has been developed in some detail in several 

 papers published in this Magazine f , and an equation has 

 been used for magnetism which is the counterpart of van 

 der Waals's equation of state for a fluid. In this theory it is 

 necessary to introduce an intrinsic field, just as an intrinsic 



* Communicated by the Author. 



t Ashworth, Phil. Mag. vol. xxvii. p. 357 ; vol. xxx. p. 711 \ 

 vol. xxxii. p. 334. 



Phil. Mag. S. 6. Yol. 43. No. 255. March 1922. 2 D 



