280 



ties, the accelerations and the forces by p's, q's, q"s, and P's, 

 the relations are g-enerally expressible by tlie equations 



(I) 

 (•■2) 

 (3) 



It will be easily seen that the relations above cited belong to 

 case (2). 



The greatest difficulty that we encounter in establishing the 

 relations between the effects of stress on nuignetization and the 

 strain caused by magnetization lies in the great difference of 

 strain coefficients according to the nature of the specimen. If all 

 the experiments be performed in a proper manner on one and 

 the same specimen of ferromagnetic metals, we may feel assured 

 of being able to discern the true merits of the theory, or to 

 detect its various defects, not only from qualitative [)oints of view, 

 but also in various quantitative details. 



