Vicksburg, Tuesday, July 7. As we did not move to-day, we spent the day amongst the prisoners who are by far the most numerous. Never has such lenity been shown to prisoners of war before. They are allowed to go anywhere within the lines and guard, their officers riding out in full regimentals, sash and swords, with orderlies. And groups of both parties are seen on every hand talking the matter over in a friendly way. A much better effect will result from this than if they were strict and kept them under guard. It opens their eyes to facts that before they were ignorant of, and many will be induced never again to raise arms against the stars and stripes. A brisk trade is going on. They sell their scrip for ten cents on the dollar. Canteens traded, coffee etc. given them freely. The best good feelings prevail. All are anxious to go home, where they will stay if possible.