315 
$ 6. Hani effect for Gold. The plate Au,; was prepared from a 
dutch 10 fl.-coin; this was dissolved in aqua regia, precipitated by SO, 
melted in a porcelain crucible and rolled between steel rollers. During 
the last operation and afterwards it was treated with various acids. 
From the decrease with temperature of the resistance with no magnetic 
field (see Table V) it is seen that this plate was made of purer gold 
than that which composed the wire Au, of Comm. N°. 99, which 
gave © Wa _o/W 7973 — 9,045 and was known to contain 0,03 °/, 
impurity. 
d was 0,101 mm., / approximately 1.2 amp., and R,= 0,6 to 
0,7 ohms. 
We found: 
TABLE.V. 
The Harr effect for Gold Aly: 
i zi ME: => ] at tapes, TS Cet En | 
| FE 2000 1 Te 20 eee | KL) 
H | — = ee ees es Ze | 
| RH | R.10! RH R104 | RH | R.104| 
] | | : rp | 
TSG |b 5162 SRT sh 3979 INL ABe 9.78 
| 1] 
9500 || 615 | 711 || 932 | 981 || 922 | 971 
W080} Bit 732 IDON |) 9.84! | ines) 9.96 
12220 8.85 | 125 | 11.98 9.81 | 12.00 9.82 
En EDEN ele | En hotel RN RBE ES 
| 
W 7999 = 202.106 0 | W T2937 6,7.10—6 n 
§ 7. Har effect for Silver. The plate Ag,7 was prepared from 
TABLE VI. 
The Hatt effect for Silver Agpy. 
- ata Ae ee TT : | 
| T=200°K | T=203K. || T= 149.5 K 
H IE Eme Ene | se ES wi >: || ee ae x 
RH | R.10 RH | Rio | RH. | R.104 
ee zel = TSS SS === _L = : = — 
4940 EN 2 oS ek Es 
726 ) | Relief 801 1.39 10.18 } €22 9.95 
9065 | 7.23 198 || 9.22 | 1017 || 898 | 9.91 
10270 | 8.16 195 || 1034 | 10.07 10.12 9.85 
w || 17310-602 || 147X<10-5 a 0.925 X 10-6. 
w/Wo | 1.065 | 0.00905 0.0057 
21 
Proceedings Royal Acad. Amsterdam. Vol. XV. 
