322 Kunz — HUctromagnetic Emission Tlieory of Light. 



the agreement between the theory and the experimental 

 results is so close tluit the hypothesis lias at least the value of 

 a working- hypothesis. It has been shown by the author of 

 this article* that the theory allows us to determine the absohite 

 values of the moments of the elementary magnets of iron, 

 nickel and magnetite, and that we can determine in this way 

 the elementary quantity of electricity ; the value e obtained in 

 this way agrees well with that given by Rutherford. 



While the moment of the elementary magnet can be 

 accounted for by the usual electron theory, it seems almost 

 impossible to account for values of the molecular field as high 

 as 6,560,000 absolute units in iron and 14,300,000 in magnetite. 



For if we assume the frequency n of an electron equal to 

 that of sodium light n = \ 10", the velocity of the electron 

 revolving in a circle would be equal to 



V =■ 2Trnr 

 where r is the radius of the orbit of the electron which we 

 shall assume to be of the order of magnitude 10~^ '''" 

 w = 3, 14-10"™ 



The electric force at E is equal to — ^ under the usual assump- 

 tion of uniform distribution of the Faraday tubes around the 



1 55' 10"^° 



electron E = — ,7- = 1,55-10-*. 



If we now assume that the tubes spread out in the form of 

 narrow cones in only two directions so that the part of the 

 surface of the sphere cut out by the cones is 1/1000 of the 

 whole surface, then the electric force in E will be 1000 times 

 larger than before, assuming that the properties of the isolated 

 tubes are the same as those possessed by a tube forming part 

 of the continuous electric field. E = 1,55-10~*. If now the 

 tube is moving, there is a magnetic force acting at each point 

 in the tube, the direction of the magnetic force being at right 

 angles to the plane containing the electric force and the 

 direction of the motion of the tube at the point, the magni- 

 tude of the magnetic force being the product of the electric 

 force and the component of the velocity at right angles to this 

 force. If the angle is equal to 90°, the magnetic force H will 

 be equal to 



H=E.u=:3, 14-10'. 1,55-10-' 



= 4,9-10" absolute units. 

 In this way it would be easy to account for the very high 

 values of the molecular field of the ferromagnetic substances. 



Laboratory of Physics, University of Illinois, 

 Urbana, July 14, 1910. 



*.J. Kunz : The Absolute Values of the Moments of the Elementary Mag- 

 nets of Iron, etc. Physical Eeview, vol. xxx, p. 859, 1910. 



