Mr. W. H. Mallock, A.M., will deliver the third lecture of his series on "Socialism, and the Allied Social and Economic Questions" tonight at 8 o'clock, in Emerson Hall. There will be two more lectures, making five in all, one tomorrow night and one Thursday, both at 8 o'clock in the same place. The two lectures already delivered have proved very successful, and have been on questions of great national interest.