176 E.. H.. Halli—New Action of Magnetism 
to be a constant for this metal. If the ex- 
indicating = 
riments in wold had begun with these particular plates, they 
ae probably have ended with them for the present. Owing, 
owever, to the great discrepancy observed between these re- 
sults and those obtained with the very thin plates it seemed 
desirable to go further, and I therefore constructed a plate 
using 
Gold Foil, No. 30 (A), (semé-cohesive ?). 
Length of strip when weighed = fs big 
Width % 
Area including projections sis 7 30 “s <4: 
Wet ht ane 1 grm 
Thickness i oline em. 
With this ake 
~" x V a3 
M. C. 
Apr. 20th, 6520 k X tan 48° 38’ 123 ef 10” 
skate 6600 of POS, SO 424 wea 
‘ 7 * 40° 80’ BUG cn ss 
Mean = 1250 X 10° 
This value is about twenty per cent lower than the mean of 
those obtained with the three es Nos. 4, 5, and 6, previously 
used, The discrepancy was so great, that another plate was 
made with a strip cut from the same sheet as No. 30 (A). 
Gold Foil, No. 30 (B), (semi-cohesive ?). 
Length of strip when weighed = 5°69 cm 
j “cc “ — 1:08 * 
Area including projections = 706 ° ag 
Weight e cee” “Tae ore 
Thickness = ‘00105 cm 
t will be seen that the strips (A) and (B), cut from similar 
sot as in the same sheet of metal, differ about seven per 
cent in mean thickness, he importance 0 of this fact has 
already been pointed out. The difference in thickness thus 
found was so great, that I at first supposed a mistake must aye 
been made in weighing the first strip, thereby giving too 
large : value for the weight. I therefore removed the strip 
from the glass plate and weighed it again. The result con- 
firmed the original value obtaine 
With the new plate, No. 30 (B), I found 
wad 
M. “6 bY’ 
Apr. 26th, 6760 k X tan 68° 0 139 x 10" 
6 oc 
+ gg" ee ji 9 hae ware 
Mean = 1400 x 10° 
