996 
20°3 K.). Only the alloys with a large percentage of Ag at 
T = 20°,3 K. are an exception to this rule. 
asx10-* BEES Be = 
At 7’= 290° K. the Hattcoefficient for dilute solutions is pro- 
portional to the conductivity 6,,9° . 
It would undoubtedly be of the greatest importance to systema- 
tically extend these investigations of the Harreffect in alloys at low 
temperatures, which I have, to my regret been obliged to confine 
to a single series of alloys, and to further investigate alloys of dif- 
ferent types. I hope to continue this research as soon as I can find 
a suitable opportunity. 
I gratefully acknowledge my indebtedness to Prof. KAMERLINGH 
ONNes who invited me to undertake these investigations of the HALL 
effect at low temperatures. 
