659 
Bir U is almost constant for T< 90°; with Biz U' is very small 
and for 7 > 72° K is practically constant. "Gat 
In strong fields the constant Zè approaches a limiting value in 
Te BEE VOR 
a for Bir | a’ for Bi yy 
/ ' 
@ obs. | 2 calc. 
90° | 12.4 | 12.1 || 90° | 20.6 | 22.0 
| | 
| 74.5 | 17.1 [17.4 |} 73° | 29.8 | 27.6 
20.3 | 62.1 | 62.6 || 20.3 | 54.3 | 57.3 
146 | 64.5 62.4 
| 
| | | ae Er 
accordance with equation (3). In weak fields RH for Bir, is in- 
versely proportional to the temperature at 7’ == 289° K, 90° _K, 74°,5 K. 
D 
Tables IV and V also contain the quantity C=. For 
w 
H >> 7000, Q is either a linear function of the field, or a constant *). 
Physics. — “On the Hawi effect and the change in resistance 
in a magnetic field at low temperatures. IV. Measurements 
at temperatures between + 17° C. and — 200° C. of the Haut 
effect, and of the change in the resistance of metals and alloys 
iw a magnetic field” By Benet Beckman. Communication 
N°. 1805 from the Physical Laboratory at Leiden. (Communic- 
ated by Prof. KAMERLINGH ONNES). 
(This Communication is a continuation of Comm. N° 130a in 
which the behaviour of bismuth was discussed.) 
Il. Gold, Silver, Copper, Palladium. 
§ 4. Hai effect for Gold. From the temperature decrease of the 
WT=20 Le 
— = 0,085, it is to be sup- 
wT=290 
posed that this plate is composed of purer gold than that of the wire 
resistance without magnetic field °), 
1) Cf. Ev. EvERDINGEN, Leiden Communications Suppl. no. 2. p. 57. 
2) H. KAMERLINGH ONNES and Benet BECKMAN.; Comm. N°. 129a. 
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