300 MAGNETISM 



Onnes,* made measurements at the temperature of liquid hydi. 

 of the intensity of magnetisation of iron, nickel, and m .and 



by certain inferences of that of cobalt. At this temperature the 

 bodies might be regarded as saturated, \\ith all the molecular 

 parallel. Weiss found that the magnetic moment | .me- 



molecule was very near in each case to a small integral multiple of 

 1123*5. This value he termed the " nwgneton-^ramnn-." II- 

 puts forth the theory that there is in each atom of these nil 

 at least one elementary magnet of constant moment and the 

 for all of them, and he terms this the magneton." Assuming 

 Perrin's value 68*5 x 10 22 as the number of molecules in the 

 gramme-molecule, and assigning one magneton with moment ;// to 

 each molecule in the magneton-gramme, \\e h 



68-5 X W 2 m = IK' 

 whence w = 16'4 x 10-". 



The magnetisations of iron, cobalt, magnetite, and nickel 

 respectively agree \\ith the possession per molecule of 11, 9, '. 

 magnetons ivsp-rtivcly. I"- '. tain 



extensions, and assuming that it is applicable to solids as \s 

 gases, certain results obtained by himself and 1'oex 4- on b<>< 

 above the Curie point, or the point where ti ability : 



almost to 1, appeal- to fall in line with the magneton hvpof! 

 on the supposition that the numb ;nctons changes. 



Weiss also uses IV show that in | 



solutions the magneli-ation can be expressed in terms of the 



magneton. 



i. p. 3 (1910). 



Jnur,,. :. ser. 1. (1911), pp. 274 ai 



