315 
The plate was annealed and was kept from contact with the liquid 
hydrogen in the bath by a coat of celluloid dissolved in amyl acetate. 
By immersing the same plate unprotected in the bath, so that it 
absorbed a large quantity of hydrogen it was found that the occlusion 
of hydrogen constantly diminished the Harr coefficient, as is evident 
from a comparison of the following data with those of Table VIII. 
It was observed that the change of resistance with temperature 
diminished at the same time. We found : 
an A Ken A AAO AOS a. Darke 
then ge eee IGM t= Ore w= LES 
and again ,, 7 —= 14°.5 | ieee ON te Ap EO a 
‘pdf eee an NV Ae tte Go Oe 
finally el == 290" ws 10% OA 
$ 10. Summary of results dealing with the change in the Hau 
coefficient for various metals. In the two subsequent Tables we give 
figures for the change in the Harr coefficient when the temperature 
sinks to hydrogen temperatures and in the region of liquid hydrogen 
temperatures; Â is the mean value taken from the previous tables 
at each definite temperature for each substance. 
‘TABLE IX. 
The Hart coefficient R at hydrogen temperatures. | 
ENNE TE is OE, 
el 
290° Tod: SC 104, 8,000 4.92 5c 10-4). 670 104 
| | | 
20°.3 || 9.81 10.14 602 13.68 
145 | 9,82 | 9.91 | 6.56 13.85 
Bled, We ME eee Nam ae 
TABLE X. 
Rr 
Change of the HALL coefficient Re 
290°K 
| on cooling to and in the region of liquid | 
hydrogen temperatures. | 
ee A a TN Mn LA eae 
2009 || 1 | 1 1 I 
2003 | 1.355 | 1.265 | 1.345 | 2.03 
145 || 1355 | 1.24 | 1.335 | 205 
| 
pi 
