166 EF. H. Hali—New Action of Magnetism 
to be smaller than the analogous action in the case of a current 
in tin. 
I now go on with an account of further investigation of the 
henomenon actually discovered and already in some measure 
described in my previous article. When writing that article it 
2, of the differ 
ence of potential per cm. on the longitudinal axis of the gold 
leaf strip to that per cm. on the transverse axis. There were 
seemed to me instructive to deduce the ratio 
thus obtained for the experiments made values of Ez ranging 
from 3,000 to 6,500 according to the strength of the magnetic 
field.* 
M 
* would prove 
to be a constant, not only for different strips of one metal, but 
for all conductors. Subsequent experiments showed that this 
was not the case, and in this article the results obtained will be 
At that time I supposed that the ratio - 
expressed by the ratio 
- , where HK’ has the same significa- 
tion as before, while M now expresses the strength of the mag- 
netic field in cm.-grm.-sec. units and V= Ss t the strength of 
the primary current divided by the area of section of the con- 
ductor. This ratio does not prove to be the same constant for 
different metals but for any particular metal it seems much 
more nearly a constant than the ratio 
be 
FE’ given above would 
force in obedience to the perfectly well known laws o 
*In obtaining this latter quantity, which was called M, a serious error was 
made and the value given was probably not much more than half what it should 
have been. This fact was mentioned in a note when the article in question was 
republished in this Journal, Mar., 1880, p. 200, and p. 235. 
be tity V may be said to bear an intimate relation to the absolute ve- 
locity of the electricity, for if we were to take as the unit velocity of electricity 
that of a unit current flowing through a conductor of unit cross-section, the ve- 
locity in any particular case would be a quantity > 
