It was through an atmosphere of scalding heat and stifling dust that the brigade marched up the bluffs of Bayou Sara and over the rounded eminences which stretched on to Port Hudson. The perspiration which drenched the ragged uniforms and the pulverous soil which powdered them rapidly mixed into a muddy plaster; and the same plaster grimed the men's faces out of almost all semblance to humanity, except where the dust clung dry and gray to hair, beard, eyebrows and eyelashes. So dense was the distressing cloud that it was impossible at times to see the length of a company. It seemed as if the men would go rabid with thirst, and drive the officers mad with their pleadings to leave the ranks for water, a privilege not allowable to any great extent in an enemy's country. A lovely crystal streamlet, running knee-deep over clean yellow sand, a charming contrast to black or brown bayous with muddy and treacherous banks, was forded by the feverish ranks with shouts and laughter of child-like enjoyment. But it was through volumes of burning yet lazy dust, soiling and darkening the glory of sunset, that the brigade reached its appointed bivouac in a large clearing, only two miles from the rebel stronghold, though hidden from it by a dense forest of oaks, beeches and magnolias. It is too early to tell, it is even too early to know, the whole truth concerning the siege of Port Hudson. To an honest man, anxious that the world shall not be humbugged, it is a mournful reflection that perhaps the whole truth never will be known to any one who will dare or care to tell it. We gained a victory there; we took an important step towards the end of the Rebellion; but at what cost, through what means, and by whose merit? It was a capital idea, whosesoever it was, to clean out Taylor's Texans and Louisianians from the Teche country before we undertook the siege of Gardner's Arkansians, Alabamians, and Mississippians at Port Hudson. But for somebody's blunder at that well-named locality, Irish Bend, the plan would have succeeded better than it did, and Taylor would not have been able to reorganize, take Brashear City, threaten New Orleans, and come near driving Banks from his main enterprise. As it was we opened the siege with fair prospects of success, and no disturbing force in the rear. The garrison, lately fifteen or twenty thousand strong, had been reduced to six thousand, in order to reinforce Vicksburg; and Joe Johnston had already directed Gardner to destroy his fortifications and transfer all his men to the great scene of contest on the central Mississippi. Banks arrived from Simmsport just in time to prevent the execution of this order. A smart skirmish was fought, in which we lost more men than the enemy, but forced Gardner to retire within his works, and accept the eventualities of an investment.