554 Intelligence and Miscellaneous Articles. 
direction of the crystallographic axis, as upon that of the dominant 
cleavage. The phenomena observed, whether with natural crystals 
or with diamagnetic or slightly magnetic masses, prepared so as to 
imitate the molecular arrangement of crystals, leave no doubt upon 
this subject. ‘The planes of cleavage place themselves equatorially 
in diamagnetic, and axially in magnetic substances. From this fact 
these physicists have thought they might conclude that the elective 
polarity of crystals, or of bodies which resemble these, depended on 
the condensation of the molecules (each of them being regarded as a 
centre of action), which is greater in one direction than in the other. 
Serious objections may be made against this opinion. The most 
important is that of M. Matteucci, who has ascertained that a needle 
of crystallized bismuth, in which the planes of cleavage are parallel 
to the length, tended to place itself equatorially with greater force 
when these planes are vertical than when they are horizontal. Still 
more recently (Comptes Rendus, Sept. 14, 1857), M. Matteucci has 
published some experiments on magnetism by rotation which appear 
to prove that the direction of the planes of cleavage, relatively to the 
lines of force of magnets, acts otherwise than by the distribution of 
the molecules considered separately, in respect of their magnetic 
mass. Hitherto experiments of this kind have only been made upon 
diamagnetic or slightly magnetic bodies. I proposed to try whether 
strongly magnetic bodies, such as iron, would not disclose analogous 
phenomena. 
I had in my possession some fragments of materials prepared for 
the manufacture of cast steel by the process of M. Chenot. These 
are very pure iron ores, reduced either by hydrogen or by car- 
bonic oxide, and then compressed by the hydraulic press. In this 
operation each grain of the reduced mineral is crushed and forms 
a little lamella, which places itself perpendicularly to the direc- 
tion of the pressure. These materials were carefully cut into square 
prisms, in such a way that the direction of the lamellee was parallel 
to the length of the prisms, and at the same time to one of the 
lateral faces. I suspended these prisms either above a small mag- 
netized bar at the distance of a few centimetres, or over a strong 
horseshoe magnet; in the latter case the distance was increased to 
24 centimetres. Such a distance evidently prevents all objection 
relative to some difference of thickness which the prisms might have 
presented, notwithstanding the care taken in their formation. 
By means of a watch with a seconds-hand, I counted the duration 
of 40 oscillations of a determined magnitude. The want of a proper 
chronometer slightly diminishes the exactitude of my observations ; 
but I have convinced myself that the utmost error of reading was 
not more than one second. Moreover, the differences upon which 
the proof of the phenomenon rests, were never less than 12 seconds. 
The numbers given are the average of several experiments, between 
which, however, there were but slight differences. 
To avoid the influence of a certain quantity of magnetism re- 
maining in the specimen to be investigated, each determination in- 
cluded eight observations made by presenting successively each of the 
lateral faces of the prism to the magnet, and turning the bar each time, 
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