ELECTRO-MAGNETIC EXPERIMENTS AND OBSERVATIONS. 469 



2. Zinc South. 



When the needle was presented to the portions of the 

 wire in the magnetic meridian 1, 2, 3. 



1. Above the wire, deflection - to E. 



2. Below - - to W. 

 but in other parts of the wire no sensible deflection. 



3. Zinc West. 



In this position there are two parts of the wire in the 

 magnetic meridian 4, 5, which present reversed results. 



1. Above that portion, number 4, deflection to E. 



2. Below - - 4, - to W. 

 but 3. Above - - 5, - to W. 



4. Below - - 5, - to E. 



4. Zinc East. 



In this position the influence of the portions 4 and 5 were 

 exactly as in the last position of the zinc. At first sight the 

 results of former experiments ought to have led us to expect a 

 difference ; but a little reflection will shew, that if these effects 

 are produced by a current passing from the zinc to the copper, 

 by the connecting wire, when the zinc is west, the current 

 must pass northward through 5, and southward through 4 ; and 

 in the opposite directions through both, when the zinc plate 

 is placed to the east of the copper. This circumstance coun- 

 teracts the effect of turning the plates, and the appearances 

 agree with the result of our previous experiments, no less than 

 with those that follow. 



The phenomena of electro-magnetism appear to favour the 

 idea of currents capable of affecting the needle differently, 

 passing in opposite directions, and on opposite sides of the 

 connecting wire, from the two metals forming the galvanic ar- 

 rangement j and the results which we obtained with the bent 

 wire, prove that the influence of the relative position of the 



zinc 



