Ordinarily a substance composed of asymmetrical molecules is paramagnetic, but if the elementary magnets are so conditioned by their strength and concentration that mutual action between them is possible, then the substance is ferromagnetic. In all cases however it is the diamagnetic condition that is initially set up - even iron is diamagnetic - though the diamagnetism may be completely masked by the superposed paramagnetic or ferromagnetic condition.
He also investigated the diamagnetic and paramagnetic properties of substances; and was keenly interested in the phenomena of electrochemical decomposition, accumulating much evidence in favour of Faraday's law and proposing a modified statement of it which was intended to cover certain apparent exceptions.
For small bodies other than spheres the coefficient will be different, but its sign will always be negative for diamagnetic substances and positive for others; hence the forces acting on any small body will be in the same directions as in the case of a sphere' Directing Couple acting on an Elongated Body.
For all diamagnetic substances, except antimony and the value of K was found to be independent of the temperature.
The 10th series (1845) contains an account of his researches on the universal action of magnetism and diamagnetic bodies.
Then followed a long series of researches, mostly published in the same journal, on the properties of magnetic and diamagnetic bodies, establishing results which are now part and parcel of our magnetic knowledge.
De Phys., 18 95, 4, 204) of the specific susceptibility K of other diamagnetic substances at different temperatures.
In the 25th series (1850) he made known his discovery of the magnetic character of oxygen gas, and the important principle that the terms paramagnetic and diamagnetic are relative.
It can be shown 3 that in a uniform field an elongated piece of any non-crystalline material is in stable equilibrium only when its length is parallel to the lines of force; for diamagnetic substances, however, the directing couple is exceedingly small, and it would hardly be possible to obtain a uniform field of sufficient strength to show the effect experimentally.
When the two electrodes are ferro-magnetic, the direction of the current through the liquid is from the unmagnetized to the magnetized electrode, the latter being least attacked; with diamagnetic electrodes the reverse is the case.