| 
| 
. 
' connection 
__ (809.) 
Cuapr. VIL, § 5.] 
hammer has enumerated above 200 of his publica- 
tions or articles, on a vast variety of subjects; but 
of all these, only a single tract of a few pages will 
perhaps be ultimately remembered. As I before 
remarked, his mind, though capable of continued 
application, appears to have wanted the sort of con- 
centration which prolonged physical researches re- 
quire, and the school of philosophy in which he was 
considered by his own countrymen as a proficient, has 
ELECTRICITY.—OERSTED—DR FARADAY. 
977 
never been fruitful in researches based on Induc- 
tion. 
In November 1850, the fiftieth anniversary of his _ (806.) 
connection with the University of Copenhagen was His death. 
celebrated by a jubilee, Though in his 74th year, 
his activity was unimpaired, and he continued his 
lectures and other employments until within a few 
days of his death, which occurred on the 9th of March 
1851, closing a life full of years and honour. 
§ 5. Dr Farapay.—Progress of the Theory of Electro-Chemical Decomposition—Volta-Electrie 
Induction—Magneto-Electricity—Diamagnetism—Optical Changes induced by Magnetism.— 
Professor Pliicker—Magneoptic Action. 
(807.) Immeasurably the larger part of what we know 
Eminent with regard to the nature and laws of electricity and 
paind of its connection with Magnetism, so far as it has been 
day. developed since the discovery of Oersted, is due to 
the genius and perseverance of one man—MIcHAEL 
Farabay. 
(808.) This eminent philosopher was born, I believe, in 
His early “ 1791. He was originally “a bookseller’s apprentice, 
history,and __very fond of experiment and very averse to trade.” 
with Davy In 1812 he sent to Sir H. Davy, then at the height 
andthe —_ of his reputation, a copy of a set of notes taken at his 
sera lectures, desiring his assistance ‘‘ to escape from trade, 
"and enter into the service of science.” To the credit of 
the popular and distinguished chemist, he gave Mr 
Faraday a courteous answer, and appointed him as 
chemical assistant in the Laboratory of the Royal In- 
stitution in March 1813, Leaving England to travel 
in the autumn of the same year, Davy engaged Mr 
Faraday to accompany him as secretary and scien- 
tific assistant; they returned in April 1815, and 
from that time to the present Mr Faraday has 
been constantly engaged in the scientific business 
of the Royal Institution, which is as completely 
associated with his numerous and splendid dis- 
coveries as Cambridge is with those of Newton, 
and Slough with those of the elder Herschel. By 
a rare, perhaps unexampled good fortune, that esta- 
blishment, founded principally for the promotion 
of original research and the promulgation of dis- 
coveries, has been indebted during the first jifty 
years of its existence to the talents of two men only, 
for a succession of new scientific truths which might 
have done credit to a whole academy; indeed, if 
to the names of Davy and Mr Faraday we add 
that of Young, who here first promulgated the doc- 
trines of the Interference of Light, there is scarcely 
an academy in Europe which has within the same 
period added so extensively to our choicest stock of 
original science, 
Partly in consequence of his official duty of bring- 
Sac of ing forward and explaining the most important cotem- 
cations. Porary discoveries, partly also in consequence of his 
his Re- | Own matchless talent of elucidating, by original illus- 
searches on trations, if not by new facts, whatever he undertakes 
eervoleg VoL. I. 
to expound, the variety of subjects on which Dr Fara- 
day has made essential additions to our knowledge 
is so great that it is difficult to comprehend them 
under one section. In conformity, however, with our 
plan of suppressing minor facts, and insisting on the 
most important, I shall confine myself to a summary 
statement of his main discoveries connected with 
Electricity and Electro-Magnetism as contained in a 
continuous series of “ Researches,” published in the 
Philosophical Transactions between 1831 and the 
present time; which, when collected (as they have 
been in a distinct form), now fill three closely 
printed octavo volumes. It would be difficult to 
name in the history of any progressive experimental 
subject so large an amount of research prosecuted 
for so long a time in so methodical a manner and 
with such remarkable uniformity in plan, and with 
such unvarying success, 
I shall only farther premise that Dr Faraday’s 810.) 
earliest essays were naturally of a chemical charac- Electro- 
ter. In 1820 he assisted Davy, in prosecuting Oer- eons 
sted’s researches on the relations of Electricity and } 
Magnetism, and the following year he himself suc- 
ceeded in producing, for the first time, the continuous 
rotation of a magnet round an electric conductor, and 
the converse rotation of the conductor round the 
magnet (798), These experiments were the germ 
of others which continued to interest philosophers as 
well as the curious public for along time after. But 
it was in 1831 (when the author had attained his 40th 
year) that the genius of Dr Faraday was displayed 
in a commanding manner by the appearance of his 
First and Second series of the Researches on Electri- 
city, which have not perhaps been surpassed by even 
the most brilliant of their successors. The subject was 
the Induction of Electric Currents from other Currents 
and from Magnets. But we shall find it most con- 
venient to take an order different from that of the 
discovery, and to present the main results of Dr 
Faraday’s electrical labours under the following yreads of 
heads :— his chief 
I. The law of definite Electro-chemical Decompo- “mi pbsen 
sition, and the theory of the pile connected therewith. "tical ais- 
II. The Induction of Electric Currents from other coveries. 
6H 
