A correspondent is out in the New York Times of the 9th inst., claiming that " it cannot be refuted tha1 Dr. C. T. Jackson, of Boston, is the first inventor of the electric telegraph." He refers to the fact that Dr. Jackson and Professor Morse were together on board the packet ship Sully, from. Havre to New York, in the summer of 1881. On his leaving Paris, Dr. Jackson purchased the little galvanic battery," with its apparatus, still kept in his possession in Boston, which may in some future day become a great curiosity, as being the very little magneticinstru-ment that has been the means of all the subsequent and wonderful events ot the magnetic telegraph above and below land and sea. Upon this voyage he alleges that it is well-known to many that Dr. Jackson conducted experiments on the deck of the vessel before all the passengers, and " in his usual open, frank manner explained everything about it and its uses for telegraphic communication." It strikes us as very singular that in the midst of all the testimony that has been eliminated to prove that Professor Morse was not the original inventor of the electric telegraph, that so important a witness as Dr. Jackson should have been left alone. It is equally singular that Dr. Jackson himself should have so long concealed his just claims, if he ever had any, to this important discovery. Where are all the passengers who saw these deck experiments ? Surely there is something strange about the case, and we should advise Dr. Jackson to keep watch of his zealous friend who thus lays claim in his favor to this great discovery. It will be as difficult now to convince the American people that Professor Morse's claims to the electric telegraph are not valid, as it is to make them believe that General Washington played " second fiddle" to Alexander Hamilton, as the son of the' latter endeavors to prove.