ON ELECTROLYSIS AND ELECTRO-CHEMISTRY. 185 
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_ Report on the Present State of our Knowledge in Electrolysis and 
, Electro-chemistry. By W.N. SuHaw, M.A. 
Tue scientific aim of the theory of electrolysis has been stated by F. 
-Kohlrausch to consist in the reference of electro-chemical phenomena to 
'mechanical processes and mechanical or electro-mechanical laws. It is 
_ the purpose of this report to enable its readers to form for themselves, 
by a comprehensive survey of work done in furtherance of that aim, an 
opinion as to the real steps that have been taken towards its achievement, 
the causes which have stood in the way of its more complete fulfilment, 
and, if possible, to get some idea as to probable directions of future pro- 
gress. It is hardly necessary to say that the aim in question has not 
et been fully attained. Multitudes of experiments have been described 
in scientific publications; some generalisations and laws have been esta- 
blished, and various forms of electro-mechanical theory of electrolysis are 
at present under discussion; but they are not yet fully developed, nor, 
indeed, have rival theories been stated in such clear forms as to lead to 
the suggestion of crucial experiments. 
A very concise yet complete summary of the facts and theories relating 
_ to electrolysis and electro-chemistry up to the end of 1882 has been com- 
_ piled by Professor G. Wiedemann, and is the more valuable as its author 
is himself so successful a worker in that field. The summary is contained. 
in Wiedemann’s ‘ Electricitiit,’ mainly in the second volume. The whole 
_ of the account of electrolysis and allied subjects occupies few, if any, 
less than a thousand of Wiedemann’s ample pages. No student of elec- 
_ trolysis can fail to owe a debt of gratitude to the author of this large 
collection of facts and theories. Since its publication, however, the atten- 
_ tion of many scientific men has been directed towards electro-chemistry. 
_ Von Helmholtz in his Faraday Lecture (April 5, 1881) ! pointed out the 
importance of the subject; and the Electrolysis Committee of the British 
Association, appointed jointly by Sections A and B, after the discussion of 
the subject at Aberdeen in 1885 opened by Dr. O. J. Lodge, has, under 
his able direction, maintained the interest init. A great deal of work 
has been done, especially towards comparing the numerical values of 
electrolytic conductivity of a compound with those of its other physical 
properties ; moreover, Svante Arrhenius, in a memoir presented to the 
Academy of Sciences of Sweden in 1883, has based the numerical caleu- 
lation of a number of chemical actions upon the numbers expressing the 
electrolytic conductivity of the interacting substances. The application 
by Von Helmholtz of the second law of thermodynamics to chemical and 
ectro-chemical processes in 1877 and 1882 has led to extensive researches 
in the thermodynamics of electrolysis. The years since the close of 1882 
haye accordingly witnessed a very remarkable activity in the development 
of electrolytic subjects. Apart from memoirs on special sections in 
current scientific literature, a general survey of the field by Lodge in 
1885, forming the opening address in the discussion at Aberdeen, is 
printed in the British Association report of that year, in which, perhaps, 
the foreshortening of the subject, natural to the point of view of a leader 
' Jour. Chem. Soc. 39, p. 277. 
