Dr. E. Bouty on the Magnetization of Steel by Currents. 119 



Cerium 81-06 



Oxygen 18-94 



100-00 



closely agreeing with that above determined. 



The foregoing analysis gives for the composition of the speci- 

 men employed in the determination of the specific heat: — 



Cerium 95-10 



Didymium 3'60 



Iron 1-12 



Silicon 0-18 



100-00 



from which we find, by formula (3), the following value for 

 the specific heat of pure cerium, 



0-04479. 



If we assume the formula of the lowest oxide of cerium to 

 be CeO, then the atomic weight of the metal becomes 92, and 

 its atomic heat 4'12. If, on the other hand, we regard cerous 

 oxide as a sesquioxide, we find the atomic weight 138, and the 

 atomic heat 6*18, which agrees in a most satisfactory manner 

 with the atomic heat of the other metals. We must therefore 

 adopt the following formulae as representing the composition 

 of the oxides of cerium: — 



Ce 2 3 , 



Ce 2 . 



XVII. On the Magnetization of Steel by Currents. 

 By E. Bouty, Docteur es Sciences*. 



Introduction. 



A MAGNET may be regarded as a combination of a great 

 number of elementary magnets, differing from one 

 another in the directions of their axes and the amounts of 

 their magnetic moments. The actual distribution of these 

 magnetic elements (of which we owe the notion to the experi- 

 ment of the broken magnet) remains inaccessible to experi- 

 ment, at least as long as the integrity of the magnet under 

 investigation is preserved ; but in most cases some restric- 

 tions are imposed beforehand on the problem which simplify 

 it mnch. 



In the first place, we demonstrate that for true magnetiza- 



* Translated from a separate impression, communicated by the Author, 

 from the Annates de VEcole Normale Superieure, annee 1876, pp. 123-154. 



