From Vicksburg.
Jackson, Miss., June 9.
--Our scouts report the enemy's pickets ten miles deep, every means of approach closely guarded, and that the greatest courage and care are required to reach Vicksburg.
Grant communicates with the fleet by signal lights, which were seen last night, constantly signalling, betokening a movement or renewal of the assault, it is thought.
The roar of the enemy's mortars was heard at intervals of two seconds all night, and is continuous this morning.
Nothing from Port Hudson.
An officer captured by Grant's pickets subsequently escaped, and arrived here this morning.
He reports the Yankee army much depressed by the knowledge of Johnston massing a heavy force in their rear, and certain death in front.
Their officers say certain defeat or annihilation awaits them. 