480 ELECTRO-MAGNETIC EXPERIMENTS AND OBSERVATIONS. 



and the surfaces of the horizontal part of the rectangular 

 pieces is very close ; the upper surfaces of helices, when the 

 zinc is west or east, affording the only differences of action be- 

 tween helices and other connecting pieces, while a complete 

 inversion of poles takes place at the lower sides of a//, when 

 the zinc is to the westward of the copper. 



We beg leave to lay before the Society these details of our 

 experiments, rather as contributions toward the materials of a 

 theory of electro-magnetic action, than with the idea of dedu- 

 cing from them any speculations on the nature of this mys- 

 terious agent ; yet we cannot avoid remarking, that, while the 

 substances connecting the poles of a galvanic arrangement be- 

 come real magnets, the opposite effects of their upper and un- 

 der surfaces appear to favour the doctrine of two electro-mag- 

 netic currents, moving in opposite directions ; and that the 

 Boreal Magnetism of the interior of Right Helices, and the 

 Austral Magnetism observed in Left Helices, combined with 

 the superior energy of helices over simple wires, seem to give 

 probability to the supposition, that the two currents have a 

 natural tendency to pursue a course in the direction of those 

 spirals. 



XXXIV. 



