Electrolytic conduction: sequel to an attempt (1886) to apply a theory of residual affinity

In discussing the phenomena of electrolytic conduction, in March, 1886, I drew a distinction between simple and composite electrolytes, the former being salts such as the silver haloids, the latter, mixtures of compounds which are themselves dielectrics. Only metallic salts of certain types are simple electrolytes: thus noper -salt is a conductor. At that time we had little knowledge of the exact behaviour of simple electrolytes, so that my treatment of the subject could only be tentative and provisional. Even now the conducting salts are sufficiently studied, but from what has been learnt in the interval it is becoming clear that their structure is the determining factor. Mercuric chloride seems not to be an electrolyte, even in conjunction with water. Some salts, those of cadmium, for example, are very weak electrolytes and exert but a slight "excess" influence; these probably are but slightly "hydrolysed" in solution and for the most part simply "hydrolated," like non-electrolytes.