ANOTHER UNION MEETING IN BEhalf of the Soldiers.--The thirteenth meeting to aid in diffusing religious reading in the camps, and promoting the spiritual interests of the soldier, will be held on Sabbath evening, December 15th, at 7 1/2 o'clock, in the Union M. E. Church, Fourth street below Arch. Addresses will be delivered by the Pastor, Rev. Anthony Atwood, Rev. Thomas Brainard, D.D., Col. M. E. [sic] Gregory, Ninety-first Regiment Pennsylvania Volunteers, and George H. Stuart, Esq. A collection will be taken. Seats free to all. Under the direction of the Army Committee of the Young Men's Christian Association of Philadelphia.