From New Orleans

JNevv York, Oct. 11. The New Orleans correspondent of the Herad gives the following partic ulars of the engagement near the Atohafayla : Owing tri the iliness of General Horron that ofFicer had re.éeivèjij leave of absence and Major General Duna has heen appointed tü trio comrnand. Thh change occuned about a week ago. As tha enemy was foiind to be in great strengt and in g od position on the opposite side of tha Atohafayla, the corumandiug general thought it advisable to throw up iritrenMnjents and vvhile the larger portion of the troops were fortifying the levee, Lieutenant Colonel Leak of the Twentieth Iowa was ordered to proceed some five or six miles in advanco. He was ac compain'jd by portions of the Nineteenth Iowa and tho Twenty-Sisth Indiana together with 150 cavalry and a section of arlillery. Early on VVednesday morningtho whóle forcé oí' the enemy, consisting of Greene's, Morton's and Mayor'a brigades succeeded in quietiy örössfng tbe Atchafay! and passing betwecn tho main line" and Colonel Leak's, and completely outflanked and eut it off beforu tho movement was discovered. Col. Leak drew up hia men in line of battlo and gallantly prepared to givo the fidvancing foe a warm reception. A eharp fight of nearly half an hour oociitred in which our troops fought bravely against overpowering numbers, but at the ond of that tiiné they were cnmpolied to snrrender, the enetny having almoat entirely surroiinded thein. With the exception of the cavalry the whole were taken prisoners and the gans captured. The tormer, oonsisting of detaptmentS from the 6th, 36ih and lst Illinois regiments, succeeded in making their eacape. The prisoners, rffieers and privates, numhered 480. Wd captured a Lieutenant Colonel and tvvelve men. Major General Dana advanced with his whole iorce as soon as possible, and our lust idvioes 6tate that the eqemy were in full retreat, they having fallen back five miles aa soon as thuy saw the división advancing toward thein. Ii this is trut the tables wíl] be turned upon thein. as they are botween the MÍBSÍssippi and Atchafayla Rvers, and to escape over the latter they will be compelled to leave the prisoners aad the artillery behind thera. %3T The morUlity is said to be three times greater in Grant's army than in the Army of tbe Potomao. The water and the wcather, probably.