350 Dr. Hare on the Theories of Electrical Phenomena. 
-51. Hence in a battery consisting of one galvanic pair excited 
by reagents of great chemical energy, and conducting power, the 
electro-magnetic effects are preéminent; while De Luc’s electric 
columns consisting of several thousands of minute pairs, feeble 
as to their chemical and conducting efficacy, are preéminent for 
statical spark-giving power (48). This seems to be quite consis 
tent, since on the one hand, the waves of polarization must be 
larger and slower, as the pairs are bigger and fewer; and on the 
other hand smaller and more active, as the pairs are more minute 
and more numerous. 
On the perfect similitude between the Polarity communicated to 
Tron Filings by a Magnetized Steel Bar, and a Galvanized 
Wire. 
52. If by a sieve, or any other means, iron filings be duly 
strewed over a paper, resting on a bar magnet, they will all be- 
come magnets, so as to arrange themselves in rows like the links 
of achain. Jach of the little magnets thus created, will, at its 
outermost end, have a polarity similar to that of the pole (of the 
magnet) with which it may be affiliated. Of course the result- 
ing ferruginous rows formed severally by the two different poles 
of the bar, will have polarities as opposite as those 0: 
said poles. 
53. In an analogous mode, if two wires be made the media of a 
galvanic discharge, iron filings, under their influence, will receive 
a magnetic polarity, arranging themselves about each wire like so 
matiy tangents to as many radii proceeding from its axis. ‘Those 
magnetized by one wire reacting with such as are magnetized by 
the other. 
54. ‘The affections of the ferruginous particles during the con- 
tinuance of the current so called, are precisely like those of the 
same particles when under the influence of the bar magnet. 
The great discordancy is in the fact, that the influence of the 
magnet is permanent, while that of the wire is indebted for ex- 
istence to a series of oppositely polarizing but transient impulses 
which proceed towards the middle of the circuit from each side, 
so as to produce reciprocal neutralization by meeting midway. 
z e effect upon the filings, as originally pointed out by 
Oersted, is precisely what would arise were the ponderable mat- 
ter of the wire, resolved by each impulse into innumerable little 
magnets, situated so as to form tangents to as many radii pro 
ceeding from the axis of the wire. 
were such as above supposed. When the discharges thr 
them concur in direction, they attract, because the left side of 
one is next the right side of the other, bringing the opposite Pp 
