DECEMBER 25TH.—Mr. Ely, the Yankee member of Congress, who has been in confinement here since the battle of Manassas, has been exchanged for Mr. Faulkner, late Minister to France, who was captured on his return from Europe. Mr. Ely smiled at the brown paper on which I had written his passport. I told him it was Southern manufacture, and although at present in a crude condition, it was in the process of improvement, and that “necessity was the mother of invention.” The necessity imposed on us by the blockade would ultimately redound to our advantage, and might injure the country inflicting it by diminishing its own products. He smiled again, and said he had no doubt we should rise to the dignity of white paper.