THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



APRIL 1890. 



XXXII. On Magnetization in Strong Fields at Different Tem- 

 peratures. By H. E. J. G. du Bois, of the Hague*. 



[Plate Vin.] 



§ 1. INTRODUCTORY.— Prof. Rowland, in summarizing 

 his well-known magnetic researches (1873), thus 

 carefully expresses himself : — 



" (7) Iron, nickel, and cohalt all probably have a maximum 

 of magnetization, though its existence can never be entirely 

 established by experiment, and must always be a matter of 

 inference ; but if one exists, the values must be nearly as 

 follows at ordinary temperatures. Iron when 53 = 17500 or 

 when 3=1390; nickel when 53 = 6340 or when 3 = 494; 

 cobalt when 53 = 10000 (?) or when 3 = 800 (?) " f . Until 

 lately, nothing decisive was done in the matter, apart from 

 occasional announcements of 3 having been found > 1390 for 

 iron; and Rowland's values had to be adopted by experi- 

 menters, including myself (Phil. Mag. Nov. 1887){. Mr. 

 Shelford Bidwelfs experiments on the lifting-power of 

 divided ring-electromagnets (up to .0 = 585) furnish important 



* Paper read before the Physical Society of Glasgow University, Nov. 8, 

 1889 ; a synopsis of results had been communicated to the Brit. Assoc, 

 Newcastle (see Proceed. Sect. A, Sept. 17, 1889 Report). 



X Rowland, Phil. Mag. [4] xlviii. p. 339 (1874) ; reduced to C.G.S. 

 units. 



% Compare Fromme's comments, Wied. Ann. xxxiii. p. 234 (1888). 



Phil. Mag. S. 5. Vol. 29. No. 179. April 1890. 2 A 



