In a lecture delivered at Bellast. a few da8 ago, Mr. J. B. Lindsay showed that much yet remained to be done in the beautiful ap plications of science to telegraphic purposes. Mr. Lindsay said that he had recently insti tuted a series of experiments with the view ot testing an idea that he had formed some fifteen years ago,—that no submarine wires are necessary for the transmission of electri city. In explanation of this principle, be said :—" I shall localize the case, in order to render it intelligible. Suppose a wire con nected with the copper end of the battery to be led down to the shore, and connected with a sheet of metal laid in the river. Suppose a wire from the zinc end taken to Broughty Ferry, and soldered to a metallic plate placed also in the river. Suppose similar plates laid in the river on the Fife side, at Newport and South Ferry, and these joined by a wire hav ing in its course one or more telegraphs.— Suppose now that a charge of electricity is sent through the wire on the Dundee side, this current may make its circuit trom the copper to the zinc either by leaping four miles through the water from Broughty Ferry to Dundee, or by a leap of two miles across the river to the other wire at South Ferry, and another leap of two miles from Newport to Dundee. In such a case, I have found that part,of the electricity does not go across, and part of it does; but the part of it that does go across is sufficient to work one or ten thou sand telegraphs."—|Ex. The same facts as those set forth above were presented in the October number of the "Edinburgh Review" for 1849. Experi ments were also made by Mr. Thomas Tay lor, formerly of this city, now of Boston, two years ago down at the Narrows in sending the electric current through part of the sea with out a wire. We have had a diagram of his plan, and an account of his experiments in our possession for more than a twelvemonth. It is impossible to employ fresh water lakes as an slectrie medium, but salt water answers very well.