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Art. XX — Magnetical Experiments , designed to illustrate 
the Manner of the Existence of the Magnetical Principle in 
Ferruginous Bodies , and the Mode of its Development . By 
William Sgoresb yjun, F. B. S. LoncL & Edin. M. W. S. 
&c. 
The phenomena of magnetism are so curious, and the prin- 
ciple itself has become of so much importance in science, that 
any thing which throws light upon the manner of action of this 
wonderful agent, may not be unworthy of publicity. The ex- 
periments that I have to mention, were suggested by an investiga- 
tion of the manner of the existence of the magnetic principle in 
ferruginous substances. They are so simple, that I can hardly 
suppose them to be entirely new, though they were new to me ; 
yet I venture to describe them, because of the obvious illustra- 
tion they afford of several of the phenomena of magnets ; and 
this is the object I have particularly in view in detailing them. 
It is a fact that has been rendered sufficiently clear by M. 
Biot, that the magnetisms of ferruginous bodies are principles re- 
siding at all times in surprising quantity in these bodies. Iron, 
magnetic or not magnetic, has precisely the same quantity of 
the magnetic matter within it, the magnetism in the one case, 
being separated and arranged in a peculiar order, and, in 
the other, neutralised either by confusion of order, or coales- 
cence. It is a fact equally certain, that the magnetic principle, 
is, by a constitution of the metal, permanently confirmed in 
every particle, so as not to permit, by any possibility, either of in- 
crease or of diminution. X very simple experiment was found 
to illustrate this. I took a steel- wire of |th of an inch in dia- 
meter, and 10 inches in length. I notched it about £ through, 
for separation into six equal portions, and then magnetised it 
strongly, in a way that prevented the liability to consecutive 
points; that is, so as to give an equal distribution of the magne- 
tic power, to confine the poles to two, and to leave those poles 
at the extremities of the wire. The iron was then broken at 
the notch nearest to the north pole, and the attractive force of 
the fragment, on a small compass placed at the distance of six 
inches, was a deviation of 19 degrees. The next central por- 
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