INDUCTIVE AFFINITY. 207 



SIMPLE VOLTAIC CIRCLE. 



When the zinc is pure, or its surface amalgamated with 

 mercury, the zincous and chlorous attractions of the touching 

 poles of A and B are not sufficiently intense to produce these 

 effects, and combination does not occur. Let a copper plate 



FIG. 11. 



Connecting wire. 



F G H (Fig. 11.), be then introduced into the acid, and con- 

 nected by a metallic wire H K I with the zinc. The particles 

 of the acid assume chlorous and zincous poles as before, so 

 also do those of the zinc, and the chain of polarized molecules 

 is now continued through the zinc and wire to the copper, the 

 exterior particle F of which, it will be observed, comes thereby 

 to present a chlorous pole to the acid. The contiguous par- 

 ticle D of acid is thus exposed to a second induction from the 

 chlorous polarity of the copper, which increases the zincous 

 polarity of the side of D next F, and, therefore, cooperates 

 in enhancing the polarized conditions already assumed by the 

 chain of acid particles extending between the two metals. An 

 endless chain or circle of polarized molecules symmetrically ar- 

 ranged is thus formed, such as exists in a magnet of which 

 the poles are united by a lifter, in which every particle in the 

 chain has its own polar condition elevated by induction, and 

 at the same time does itself react upon and elevate the polar 

 condition of every other particle in the chain. The result of this is 

 that the primary attraction of the zinc atom z of A, for the chlo- 

 rine, cl of the hydrochloric acid B is increased, and attains that 

 degree of intensity at which the resistance to the impending com- 

 bination is overcome, and the z and cl of A and B unite. But 

 in a circle of polar molecules, in which the condition of any one 

 molecule determines and is determined by that of every other, 

 the intensity of the polar condition is necessarily the same in 

 every element of the circle. The chemical polarity, therefore, 



