ox MAGNETOSTRICTION. 



r : \'olinue of llie ovoid. 

 f' : Density „ „ „ 



The difference in the volume of the ovoids is to be attributed 

 to the slight deviation from the exact geometrical shape. 



As most specimens of cobalt contain more or less nickel, the cast 

 and the annealed samples of the metal were subjected to chemical 

 analysis, with the following results, for which our thanks are due to 

 Mr. T. Suzuki, student in the chemical department of the University. 



The specimen is not very pure, containing a small percentage 

 of nickel as an impurity. 



