8 REPORT— 1852. 
the gas supposed to be derived from electrolyzation. By a proper application of 
Nobili’s beautiful experiment of colours obtained by electrolyzation, I was enabled 
to demonstrate, that an axis of great magnetic power has_no sensible influence in 
disturbing the distribution or propagation of the electrical currents, nor the physical 
or chemical composition of the body traversed by them. Make a rectangular box, the 
longer sides of which are formed of perfectly clean plates of platina. Fill this box 
with a solution of chloride of iron, or acetate of lead, or other metallic salts, and place 
it between the poles of a very powerful electro-magnet. The coloration of these 
plates, produced by the shortest passage of a very feeble current, is found to be exactly 
the same at all points, that is, on the line of the magnetic poles, as at the distance of 
150 or 200 millimetres from that line. The magnetic power therefore does not 
change either the composition of the liquid subject to its action, nor the distribution 
of the electricity which traverses it. I remember having found formerly that the 
laws of the derived currents on a plate of tin and of the isodynamic lines, were not 
disturbed by the influence of a very strong electro-magnet. I have also studied the 
influence of the magnetic power of the elements on that of the body resulting from 
their combination. Although there are some examples of magnetic compounds, 
the elements of which are diamagnetic, such as protochloride of copper, one finds in 
general that the magnetical character of the compound results from that of its ele- 
ments. Pure copper, which, independently of inductive currents, is decidedly dia- 
magnetic, produces protoxide, which is indifferent or scarcely diamagnetic, and a per- 
oxide which is decidedly magnetic. The same may be said of silver; the protoxide 
is diamagnetic, and the binoxide, obtained by the pile, is decidedly magnetic. Operating 
on the various oxides of bismuth and antimony, I measured the variations in the 
magnetic power induced by different quantities of oxygen contained in these oxides. 
I have made a great number of conclusive and elegant experiments on the laws of 
equilibrium of diamagnetic bodies in the magnetic field, and on the reciprocal action 
of diamagnetic bodies. I have employed in these experiments a solution of chloride 
of iron in concentrated alcohol, so as to have the same density as olive oil, which is 
a diamagnetic body. I could thus fill the magnetic field with this ferruginous 
solution, in which floats a drop of oil, more or less large, or I could reverse the 
arrangement. At the moment in which the electro-magnet is set in action, the 
two liquids are set in movement and place themselves in equilibrium, occupying 
distinct places in the magnetic field. By adopting the proper arrangements, one 
can easily determine the form of the curved surfaces of separation of the two liquids. 
This method is delicate, and fitted for discovering the slightest difference in the force . 
of the two poles, or in their relative distance from the centre of the magnetic field. 
If the magnetic field is uniform, as one obtains it with plane polar surfaces of great 
extent, a small piece of bismuth suspended to a cocoon silk, in the manner employed 
also by yourself, is in equilibrium in the centre of the magnetic field and in the 
greater part of the equatorial line. When the magnetic field is formed by the ferru- 
ginous solution, a piece of bismuth or drop of oil floating within the liquid does not 
remain in equilibrium in the centre of the field, but flies off to the side following the 
equatorial line. The drop changes in form, and is prolonged in axial or equatorial 
direction according to its being magnetic or diamagnetic. The constant motion of 
the diamagnetic drop from the centre towards the side along the equatorial line and 
this, even when floating not at the surface but in the middle of the liquid mass, is 
not in evident accord with the beautiful experiments of Reich and Tyndall. I have 
remarked on the fact, that the motion takes place when the drop is even in the 
midst. of the liquid, in order to prove that this motion is independent of the remark- 
able elevation undergone by the ferruginous liquid along the line of the poles. 
With this method I could easily examine the mutual action of diamagnetic bodies. 
For this purpose the base of the square box placed in the magnetic field was formed 
one half of marble or wood, the other of bismuth. This base was covered with a 
thin stratum of ferruginous liquid, and of oil three millimetres in thickness. The 
line of junction of the marble and bismuth was alternately axial aud equatorial. I 
was never able to discern the slightest dissymmetry in the form of the surfaces of 
separation of the two liquids, which might be attributed to the influence of the two 
very different substances, marble and bismuth, as regards their magnetic power. In 
the same way, I have never been able to discover any mutual action at the moment 

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