New York, Nov. 5. A New Oi'leans letter t the Herald says Gen. Wertzel's briffade landed at Donaldsonville on tba25tb, wout thence to Thibodeaux, vvhere t had a slight engagement, capturing 20 rebels. An otber force was sent to attack lbo rebels in the rear, under Col. Thomas, and two ironclüds and twogunboats, under Capt. Buchanan, WÏth tlm 2Lst Indiana, which ho landed at Brashear City, while the gunboats ?o to Franklin to destroy the gunboats said to be thero. ïhe rebels destroyed all tho produce at Donaldsonvüle prior to tho arrival of Wertzel.