198 



WEBER ON THE CONNEXION OF DIAMAGNETISM 



molecular currents, by which assumption the generation and 

 changes of the magnetism of iron are rendered quite independent 

 of the idea of magnetic fluids, and are reduced to the assumption 

 of moveable electric fluids alone. 



According to the assumption already made (at the end of the 

 first section) of a definite capacity of rotation on the part of the 

 molecules, the character of every body, in magnetical respects, 

 is determined by two distinctive marks, — 1st, by the product of 

 the magnetic moment of a molecule (in the direction of its mag- 

 netic axis) into the number of molecules of the body ; 2ndly, by 

 the constant to which we have given the name of the molecular 

 force of direction. The product is denoted above by Ufu,, the 

 constant by D. Setting in the case of iron, 



nfi =2324-68, 

 D = 276-39, 



where the number of molecules n is referred to the unit of mass, 

 we obtain from the formulae given at the end of the first section, 

 reference being made to the unit of mass instead of to the unit 

 of volume, the density of iron being taken at 7 '7 ^3 and the 

 numerical factor S referrino; to a bar 100" 2 millimetres Ions: 



and 3*66 millimetres thick, that is, S =^775 — the following 



contemporaneous values of X and m. 



It will be observed that these calculated values differ but 

 little from those contained in the foregoing table, and which 

 were derived from observation. 



