Washington, Aug. 26. - Orders have been issued to muster out the following: Fourth Pennsylvania iniantry, Sixth Illinois infantry, Second Wiseonsin infantry, three Louisiana light batteries, two Rhode Island light batteries, two Iowa light batteries, two Oregon light batteries, First Wisconsin light battery, two troops of Kentucky cavalry, light battery A of Missouri, light artillery Twenty-seventh light battery of Indiana artillery, and light batteries A, B and C of Pennsylvania light batteries. Where the troops mustered out are not specially designated they include all of that arm of the service from the states named. Washington, Aug. 30.- The following troops have been ordered mustered out: Ninth Massaehusetts, from Montauk to South Framingham, Mass., where they will be mustered out; Seventh Illinois, from Middletown to Spring-field; First Illinois, from Montauk to Springfleld; Fifth Illinois, from Lexington to Springfleld; Sixty-fifth New York, from Camp Alger to lo; Fifth Ohio infantry, from Fernandina, Fia., to Columbus, Ohio; First Wisconsin, from Jacksonville to Camp Douglas.Wis.; Third United States volunteer cavalry (Grigsby's) at Chickamauga; Fourth Texas at Austin, Tex.