222 INDUCTIVE AFFINITY. 



The zinc or positive metal, too, always forms a proto-com- 

 pound in dissolving, which is a saline body. The order of 

 the chemical changes in the exciting fluid therefore is as follows : 

 The zinc in decomposing a binary compound and forming a 

 binary compound, liberates an atom of its own class ; which 

 atom repeats the same actions; supplying at the same time 

 another atom of the same kind to act in the same manner, and 

 that another, from the zinc to the copper plate. The combining 

 bodies are always a basyle and a salt-radical, and therefore only 

 two kinds of attraction or affinity are at work throughout the 

 chain, those of a basyle and a salt-radical, the zincous and 

 chlorous affinities. Hence, in the present subject of chemical 

 polarity, we have to deal with but two attractive forces, the 

 zincous and the chlorous, as in magnetism with but two mag- 

 netic forces, the austral and the boreal. 



On the electrical hypothesis a body which is thus decom- 

 posed in the active cells, or in the cell of decomposition, is 

 called an electrolyte (decomposable by electricity), and this kind 

 of decomposition is distinguished as electrolysis. The chemical 

 expressions equivalent to these are zincolyte and zincolysis, the 

 decompositions throughout the circle being referred to the 

 inductive action of the affinities of zinc or the positive metal. 



The characters of the two constituents of a zincolyte may be 

 shortly noticed. The class of basyle constituents is composed 

 of the metals in their order as positive metals, beginning with 

 potassium and terminating with mercury, platinum and the less 

 oxidable metals. Ammonium has a claim to be introduced high 

 in this list, and should probably be accompanied by the analo- 

 gous basyles of the vegeto -alkalies, although in respect to the 

 decomposition of their salts in the voltaic circle, we have no 

 precise information. Hydrogen likewise finds a place near cop- 

 per in this class. 



At the head of the salt-radical constituents of zincolytes may 

 be placed iodine and the other members of the chlorine family. 

 These are followed by the salt-radicals of the sulphates, nitrates, 

 carbonates, acetates, and other oxygen-acid salts. Sulphur must 

 be allowed to follow the last as the salt-radical of the soluble sul- 

 phurets, and the lowest place be assigned to oxygen, as the 

 salt-radical of the soluble metallic oxides, of oxide of potassium, 

 for instance, and of water. It is unusual to speak of oxygen as a 

 salt-radical, and of caustic potash and water as salts, but the 



