GENERALITY OF MAGNETIC AND DIAMAGNETIC ACTION. 
53 
attracted, or recede as if mutually repelled. All the phenomena resolve themselves 
into this, that a portion of such matter, when under magnetic action, tends to move 
from stronger to weaker places or points of force. When the substance is surrounded 
by lines of magnetic force of equal power on all sides, it does not tend to move, and 
is then in marked contradistinction with a linear current of electricity under the 
same circumstances. 
2419. This condition and effect is new, not only as it respects the exertion of 
power by a magnet over bodies previously supposed to be indifferent to its influence, 
but is new as a magnetic action, presenting us with a second mode in which the 
magnetic power can exert its influence. These two modes are in the same general 
antithetical relation to each other as positive and negative in electricity, or as north- 
ness and southness in polarity, or as the lines of electric and magnetic force in mag- 
neto-electricity ; and the diamagnetic phenomena are the more important, because 
they extend largely, and in a new direction, that character of duality which the mag- 
netic force already, in a certain degree, was known to possess. 
2420. All matter appears to be subject to the magnetic force as universally as it 
is to the gravitating, the electric and the chemical or cohesive forces ; for that which 
is not affected by it in the manner of ordinary magnetic action, is affected in the 
manner I have now described ; the matter possessing for the time the solid or fluid 
state. Hence substances appear to arrange themselves into two great divisions, the 
magnetic, and that which I have called the diamagnetic classes ; and between these 
classes the contrast is so great and direct, though varying in degree, that where a 
substance from the one class will be attracted, a body from the other will be repelled ; 
and where a bar of the one will assume a certain position, a bar of the other will 
acquire a position at right angles to it. 
2421. As yet I have not found a single solid or fluid body, not being a mixture, 
that is perfectly neutral in relation to the two lists ; i. e. that is neither attracted nor 
repelled in air. It would probably be important to the consideration of magnetic 
action, to know if there were any natural simple substance possessing this condition 
in the solid or fluid state. Of compound or mixed bodies there may be many ; and 
as it may be important to the advancement of experimental investigation, I will 
describe the principles on which such a substance was prepared when required for 
use as a circumambient medium. 
2422. It is manifest that the properties of magnetic and diamagnetic bodies are 
in opposition as respects their dynamic effects ; and, therefore, that by a due mixture 
of bodies from each class, a substance having any intermediate degree of the property 
of either may be obtained. Protosulphate of iron belongs to the magnetic, and water 
to the diamagnetic class ; and using these substances, I found it easy to make a 
solution which was neither attracted nor repelled, nor pointed when in air. Such a 
solution pointed axially when surrounded by water. If nmde somewhat weaker in 
respect of the iron, it would point axially in water but equatorially in air ; and it 
