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HISTORY. 
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pieces of carbon cut to a point. In the autumn of 1812, he 
fired several mines in this way across the Neva at St. 
Petersburg. 
Having rejoined the army at the end of 1813 he took part 
in the campaign in France in 1814, and on the 31st of March 
entered Paris with Alexander I. Here, during his stay, he 
resumed his experiments, and he several times exhibited in the 
capital the blowing up of. mines by means of electric currents 
conveyed across the Seine. 
On returning to Munich in 1815, Schilling showed 
Soemmering a little work published in Paris in 1805, and 
entitled “ Manuel du Galvanism ” by Joseph Izarn, professor 
of physics at the Lycee Bonaparte. This book mentions 
Romagnesi’s discovery, but neither Soemmering nor his friend 
appears to have been struck by it as admitting of practical 
application. Thus they were acquainted with Romagnesi’s 
discovery, and had read his paper published at Trent on the 
3rd August, 1802, in which he announces that “Mr. Councillor 
Gian-Domenico Romagnesi hastens to communicate to the 
physicists of Europe an experiment relating to the application 
of the galvanic fluid to magnetism.” The importance of this 
discovery will be understood when it is stated that it consisted 
of the deviation of a magnetized needle under the influence of 
the galvanic current. 
With the year 1820, began a new epoch in the history of 
electricity. And from that period the future importance of 
the electric telegraph might be recognized. 
Hans Christian GErsted studied the effects of a voltaic 
current on the magnetic needle more closely than Romagnesi. 
Arago communicated (Ersted’s experiments to the Academy of 
Sciences, and Delarive in September, 1820, repeated these 
experiments with Pictet at Geneva. 
It has been stated that (Ersted was acquainted with the 
discovery made by Romagnesi in 1802. It had been, as we 
said, mentioned in Izarn’s “Manuel du Galvanism,” and it was 
likewise described in a book published at Paris in 1804 by 
Giovanni Aldini (Galvani’s nephew), and entitled : “ Essai 
theorique et experimental sur le galvanisme.” In this it was 
stated that “ M. Romagnesi, the physicist of Trente, has found 
that galvanism causes the magnetic needle to deviate.” 
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