The Yankees in Florida.
Savannah, March 26.
--The Savannah Republican, of this morning, says that the Yankees are in full possession of St. John's river, Florida.
About 2,500 Federals are at Jacksonville, Fla. They have torn up the railroad track, and are using the iron in the defence of the city.
Another special dispatch to the same paper, from Baldwin, Fla, says that a small detachment of Confederates stole upon the Yankee guard at Jacksonville, killing four and capturing three. Lieut. Strange, of the Confederate party, was wounded, and, it is feared, mortally.