Jackson is being evacuated by the enemy, all but one army corps having marched in the direction of Vicksburg at 4 o'clock this morning. The remaining corps, the NINTH, will probably move to-night or to-morrow morning.

It is generally understood in the Yankee army that Mobile will be the next point of attack, their army proceeding from Vicksburg to Memphis, and there by rail to the Mobile and Ohio Railroad.

He reports large quantities of ammunition being landed at Vicksburg, chiefly for artillery.

My scouts report no enemy this side of Pearl River, except scouts one-half mile this side of Jackson.

I am, colonel, very respectfully, your obedient servant,

WIRT ADAMS,

Colonel, Commanding.

HDQRS. FIFTH MIL., DIST., DEPT. MISS., AND E. La.,
Grenada, July 21, 1863.

Colonel B. S. EWELL, Assistant Adjutant-General, Brandon, MISS:

COLONEL: I have the honor to acknowledge the receipt of a letter from General Johnston, dated Brandon, July 17, 1863., in which he directs me to hold this district as long as possible, and, when compelled to leave it, to retire to the east, moving from point to point, as may be necessary.

The movements of the enemy below render it necessary that I should send a force in that direction to observe and check them. I have, therefore, ordered Brigadier-General George, with the State troops, to move to the vicinity of Vaiden for that purpose. As soon as I have removed the remainder of the stores from this place, I will return with the rest of my command to Panola, to operate against the enemy on the line of the Memphis and Charleston Railroad.

My ordnance stores, heavy baggage, and some supplies have already been taken to WEST Point, on the Mobile and Ohio Railroad. To-day I shall send about 100,000 pounds of breadstuffs to the same place. Since communication has been cut off with your army, about 2,000 head of beef-cattle have been sent across the country. I will continue to collect them and other supplies, and forward them as rapidly as possible, while I am able to remain in this part of the country.

I have about 50 wagons which I can use in the transportation of supplies. And as long as I can maintain my positions and protect this place, it is my intention to make it my depot for supplies, and run a regular wagon train between it and WEST Point, which will be my depot on the Mobile and Ohio Railroad. By this means I hope to get out a considerable quantity. I will keep the railroad in operation from Panola as far south as can be done with safety to transport supplies. I have ordered all the rolling-stock on the different roads, not required for that purpose, to be concentrated north of the Yalabusha River, and arranged so as to be destroyed at the shortest notice whenever it shall be necessary.

Is it necessary that the rolling-stock of these roads should be completely destroyed, if I am compelled to abandon the line of the road? Or will it be sufficient to disable them and the road (by burning bridges) so as to render it impossible to operate it for some time, and without great labor and expense to the enemy?

I am, colonel, very respectfully, your obedient servant.

JAMES R. CHALMERS.