Plot discovered to burn Willard's Hotel--
Lincoln and Old Scott Badly Scared.
Alexandria, April 20.
--A plot to burn Willard's Hotel, at Washington, was discovered last night.
Fifteen bundles of inflammable material were found distributed in various parts of the building, with slow matches attached.
Cassius M. Clay and seventy-five Border Ruffians are quartered at Willard's, and it is supposed the plot was to exterminate these scoundrels.
Abe Lincoln and Old Scott have been frightened out of seven years growth.
They are hourly expecting that the White house and other public buildings will be blown to pieces.
The citizens generally partake of the alarm, and women and children are fast leaving the place.
All along the line of railroad from Alexandria to Richmond, the troops are drilling, and the Confederate flag is flying.
The war spirit in Virginia is now thoroughly aroused, and the Capitol must soon fall into the hands of our troops.
A band of seventy-five border ruffians are quartered in the east room of the White House at Washington, and great indignation is expressed at such a desecration. 