Current value of slaves.—Rebel War Clerk.

MAY 4th. –Met Win. H. B. Custis, Esq., to-day in the square, and had a long conversation with him. He has made up his mind to sign the ordinance. He thinks secession might have been averted with honor, if our politicians at Washington had not been ambitious to figure as leaders in a new revolution. Custis was always a Democrat, and supported Douglas on the ground that he was the regular nominee. He said his negro property a month before was worth, perhaps, fifty thousand dollars; now his slaves would not bring probably more than five thousand; and that would be the fate of many slaveowners in Virginia.