(81) 

 1 1 



— ///,r/ and —/£'«<•«■- 



(see § 12 of Riecke's paper) where e denotes the charge in electro- 

 magnetic units, Up and //„ denote masses and Cp and e„ velocities 

 of tl.e charged particles. Of course the product of these quantities 

 can never be otherwise than positive. Now for the galvauomagnctic 

 difference of temperature always a positive value, for the thermo- 

 magnetic difference of potential in weak fields however a negative 

 value was found. The regularity with which this phenomenon showed 

 itself, appearing f. i. from the graphical representation, proves that 

 theie can be no question of errors of observation ; none of the known 

 thermomagnetic phenomena can cause a systematic error; hence the 

 negative sign of the thermomagnetic difference of potential in weak 

 fields is not to be reconciled with Rieckk's theory in its present 

 form . 



But even if we will not insist upon this negative sign in the 

 weak fields, the positive value in stronger fields leads in connection 

 with the other quantities to conclusions, which give rise to the 

 question whether in the theory everything has been taken into con- 

 sideration. 



For the calcuJatiini 1 chose the magnetic field 6 lOU and the series 

 of observations A. We find then 



a = 1,05.10-1° /, =-8,83.10-^ c = 4,56.10-2 rf=—l, 63.10-0. 



In the calculation of a and h for the resistance of the bismutli, 

 which has not yet been determined by nie, was taken the value 

 which Fleming and Dewar found in a field of 6100, namely 

 134.10=5 in C. G. S. units. 



The formulae 5 and 6 give 



«=—0,157.10-5 ,, = 8,84.10-5 



whence we deduce further 



g, = - 1,304 g„ = 0,0-16 



^=8,3.105 —=0,0052.105 



