( 408 ) 

 vuN Ettjnusuauökn umi Nkknöt ') 



C', = 0,1341 C'i = 0,S8S2 



MiiRuetic lield. 



Perceutagc iucrease. 

 observed. 1 calculated. 



Difl'cruuc-i'. 



Fleming and Dewak -) 



Temp. 19°. 6', = — 0,03081 Cj^^O.iSOS 



Mametic field. 



Percentage iucrease 

 observed l calculated. 



Differcucc. 



2150 



5500 



11.2C0 



ü,3 

 13,0 

 00,9 



1,2 

 G,fi 



01,9 



— 5,1 



— 7,0 



+ l,ü 



A« appearis fiom tlio negative s^ign of (\ and the larg'c deviations, 

 the observations in the last table cannot be represented by our for- 

 mula. But from this discussion it would appear that the accurate 

 representation of my three results by a formula with two constants 

 signifies more than would at first be expected. 



4. Variation of coijductiviti/ for Itcut. 



a. Measurements. It being our object to observe all the [dieno- 

 mena as far as possible under the same circumstances, we in tiiis 

 case had to determine the variation of temperature at different distances 

 from the source of heat, in order to calculate from it the variation 

 of the conductivity. 



We therefore first observed the temperature in the stationary con- 

 dition without magnetic field, then that temperature in the new 

 stationary condition in the magnetic field. It appeared however after 



1) Wied. Anu. 33 p. 474, 1888. 



=*) Proc. Hoy. Soc. 60, p. 423, 1896. 



