It was not, however, a defeat which involved the loss of every advantage previously gained. BLÜCHER was not _driven_ from the Field: but, on the contrary, he maintained it during the night, with the exception of the Villages of Ligny and St Amand in his front; thus facilitating the orderly retreat of his own Army, and, at the same time, affording a considerable degree of security to the direct line of retreat of the Duke of WELLINGTON. The defeat certainly compelled the latter to retire on the following morning, whatever might have been his success at Quatre Bras; but so long as BLÜCHER had it in his power to fall back in such a manner as to effect his junction the next day with WELLINGTON, the advantage which accrued to the common object of the two Commanders was of the highest importance. They would then unite after the concentration of each Army had been accomplished; hitherto, they had been compelled to meet their opponents before they had succeeded in collecting their respective forces. If, however, WELLINGTON had been unable to maintain his ground against NEY, and NAPOLEON had in this manner succeeded in beating both Armies in detail; or, if the Prussian defeat had been followed up by a vigorous pursuit, the loss of the Battle of Ligny might have placed both Armies in a critical position. The struggle at Ligny was undoubtedly of a most desperate and sanguinary character. It was, almost throughout, one continued village fight; a species of contest which, though extremely harassing and destructive to both parties engaged, was that most likely to prove of a long duration, and consequently to afford a better prospect of relief by the promised support from WELLINGTON, or by the hoped-for junction of BÜLOW. * * * * *