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from the book of Aldini that Oersted, at the time he finished it, was still in communication with him, for he says at the end (page 376), he had not been able to add the information received from Oersted, Doctor of the University at Copenhagen, about the galvanic labours of scientific men in that county, nor that relating to new apparatus invented by himself. In 1813 Oersted had been again in Paris.
Who would suppose that Oersted did not know everything contained in Aldini's book, in which even the index points to Romagnosi's discovery in the following words: "Romanesi a fait des tentatives sur l'aiguille aimantée, page 191"?
For Izarn's " Manuel" of 1805, above quoted, the mention of Romagnosi's discovery is evidently taken from Aldini's book of 1804.
The words there are: " D'après les observations de Romagnési, physicien de Trente, l'aiguille déjà aimantto et que l'on soumet au courant galvanique, éprouve une déclinaison." Now, this is literally what, since 1820, the world has been accustomed to call Oersted's discovery.
As Oersted must have known Romagnoei's experiment, it would have been an additional credit to him, if, in
