186 REPORT—1890. 
of discussion, is somewhat conspicuous. There is, moreover, a short but 
very interesting sketch of the subject in 1887 by one of the founders of 
its new development, published in the‘ Hlectrotechnische Zeitschrift,’ June 
1887, under the title of ‘Die gegenwirtigen Anschauungen tiber die 
Electrolyse von Loésungen,’ by F. Kohlrausch, and a brief statement ot 
the problems in the subject was given by G. Wiedemann at the meeting 
of the British Association at Manchester in 1887 (‘ Report,’ p. 347). 
The order of arrangement of this report will be :— 
(1.) A general statement of the actions, physical and chemical, pro- 
duced by the passage of electricity through a typical electrolytic cell. 
This is introduced for the purpose of securing definiteness in the con- 
ceptions and language, and to set forth the phenomena which any theory 
of electrolysis must primarily be able to explain. It will also serve asa 
guide to the classification of the experimental data available for testing 
or illustrating electrolytic theories. 
(1I.) A statement of those generalisations and laws which are accepted 
by all workers in the subject. References will be given to the original 
sources of the evidence upon which these laws are based, but a detailed 
historical account of the establishment of the laws will not be attempted, 
although some of them may only have been accepted after prolonged 
discussion. 
(III.) A short statement of the hypotheses and of the partial or 
general theories of electrolysis which have been proposed and are still 
under discussion, and the experiments relating to them, including especially 
the following questions :— 
(a) What is an electrolyte ? 
(b) What are the ions in any given electrolytic decomposition, 3 
including the cases of mixed electrolytes ? 
(c) The Williamson-Clausius theory of dissociation. 
(d) Hlectro-chemical thermodynamics, including thermo-electric 
effects. 
(e) The theory of electric endosmose. 
(f) The theory of the migration of icns and of specific ionic — 
velocities. 
(g) The numerical relations of electrical conductivity with other 
physical and chemical properties of the electrolytic sub- 
stances. 
(IV.) A discussion of the experimental methods and the apparatus 
used in the determination of numerical values used in the previous 
section. 
(V.) Anaccount of electro-chemical phenomena which are not generally 
included in the term ‘ electrolytic,’ but which may be used to elucidate 
the electrolytic theories. In this section will be included certain pheno- — 
mena connected with the passage of electricity through solids and gases, 
and the conductivity of flame. 
(VI.) Electrolytic or electro-chemical phenomena which are not re- 
garded as having a direct bearing upon electrolytic theories, viz. secondary 
actions, electro-capillary phenomena, irreciprocal conduction, electro- 
striction, aud transition resistance. 
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