208 INDUCTIVE AFFINITY. 



of the other particles forming the chain must increase to an 

 equal degree with A and B, when the circle is completed, and 

 the same change must now occur in all of them that has oc- 

 curred in A and B. The pole of B next C is intensely zincous, 

 while that of C next B is intensely chlorous, whence the chlorine 

 and hydrogen cl and z of these two particles combine together. 

 At the same time, and for the same reason, the hydrogen z 

 of C unites with the chlorine cl of D; and so on, through 

 a chain of particles of hydrochloric acid of any length, till the 

 copper is reached, when the last acid particle, D in the figure, 

 yields its hydrogen z to the chlorous pole of the copper cl. 

 But the hydrogeny not being capable of combining with the 

 copper, is liberated as gas upon the surface of that metal. 



Some internal change of a similar character appears to take 

 place in the chain of polarized molecules extending through the 

 metals themselves a series of molecular detachments and re- 

 attachments, among the atoms of their polar molecules, like 

 the decompositions and recompositions in the acid, causing 

 evolution of heat and other phenomena, generally reputed elec- 

 trical, which the zinc and copper plates and the connecting 

 wire exhibit. 



The polar molecule of the metals has been assumed to con- 

 tain two atoms (like that of the acid), with the view of 

 assimilating these intestinal changes in the solid to those 

 occurring in the fluid portion of the voltaic circuit, and also 

 because it appears to account for the advantage of amalgamating 

 the zinc surface. In the amalgamated plate, it is not zinc itself, 

 but a chemical combination of mercury and zinc which is pre- 

 sented to the acid, in which mercury is the "negative" element, 

 and which might, therefore, be called a hydrarguret of zinc. 

 That combination likewise is fluid. It must constitute the 

 polar molecule, which will then consist of an atom of mercury 

 as chlorous pole, and an atom of zinc as zincous pole, and not 

 of two atoms of zinc. These metallic molecules are also ca- 

 pable of movement from their fluidity, and will, therefore, 

 place themselves in forming a polar chain with their unlike 

 poles together, as the fluid acid particles arrange themselves. 

 So that in an amalgam of zinc, of which A, E and I are polar 

 molecules (Fig. 8.), all the atoms marked cl are mercury, and 

 those marked z are zinc. It thus follows that, when by con- 

 tact with an acid he amalgam is polarized, it presents a 



