16 
Sir Humphry Davy on the 
It was perfectly evident from these experiments, that as 
many polar arrangements may be formed as chords can be 
drawn in circles surrounding the wire ; and so far these phe- 
nomena agree with your idea of revolving magnetism ; but 
I shall quit this subject, which I hope you will yourself elu- 
cidate for the information of the Society, to mention some 
other circumstances and facts belonging to the enquiry. 
Supposing powerful electricity to be passed through two, 
three, four, or more wires, forming part of the same circuit 
parallel to each other in the same plane, or in different 
planes, it could hardly be doubted that each wire, and the 
space around it, would become magnetic in the same manner 
as a single wire, though in a less degree ; and this I found 
was actually the case. When four wires of fine platinum 
were made to complete a powerful voltaic circuit, each wire 
exhibited its magnetism in the same manner, and steel filings 
on the sides of the wires opposite attracted each other. 
As the filings on the opposite sides of the wire attracted 
each other in consequence of their being in opposite magnetic 
states, it was evident, that if the similar sides could be brought 
in contact, steel filings upon them would repel each other. — 
This was very easily tried with two voltaic batteries arranged 
parallel to each other, so that the positive end of one was op- 
posite to the negative end of the other : steel filings upon two 
wires of platinum joining the extremities strongly repelled 
each other. When the batteries were arranged in the same 
order, i. e. positive opposite to positive, they attracted each 
other ; and wires of platinum (without filings) and fine steel 
wire (still more strongly) exhibited similar phenomena of at- 
traction and repulsion under the same circumstances. 
