The opportunity of the moment would all be on one side, on the side of your foe. Is there any great strain of reasoning wanted to prove that an internal war raging in a State is the least opportune time for entering upon a foreign war? At every other moment the mercantile classes of Great Britain would have looked upon a war against the United States with the utmost horror. Now, on the contrary, a large and influential party of the mercantile community has for months been urging on the Government to violently break the blockade, and thus provide the main branch of British industry with its raw material. The fear of a curtailment of the English export trade to the United States has lost its sting by the curtailment of that trade having already actually occurred. "They" (the Northern States), says The Economist , "are wretched customers, instead of good ones." The vast credit usually given by English commerce to the United States, principally by the acceptance of bills drawn from China and India, has been already reduced to scarcely a fifth of what it was in 1857. Last, not least, Decembrist France, bankrupt, paralyzed at home, beset with difficulty abroad, pounces upon an Anglo-American war as a real godsend, and, in order to buy English support in Europe, will strain all her power to support "Perfidious Albion"on the other side of the Atlantic. Read only the French newspapers. The pitch of indignation to which they have wrought themselves in their tender care for the "honor of England," their fierce diatribes as to the necessity on the part of England to revenge the outrage on the Union Jack, their vile denunciations of everything American, would be truly appalling, if they were not ridiculous and disgusting at the same time. Lastly, if the United States give way in this instance, they will not derogate one iota of their dignity. England has reduced her complaint to a mere error of procedure, a technical blunder of which she had made herself systematically guilty in all her maritime wars, but against which the United States have never ceased to protest, and which President Madison, in his message inaugurating the war of 1812, expatiated upon as one of the most shocking breaches of international law. If the United States may be defended in paying England with her own coin, will they be accused for magnanimously disavowing, on the part of a single American captain, acting on his own responsibility, what they always denounced as a systematic usurpation on the part of the British Navy!

In point of fact, the gain of such a procedure would be all on the American side. England, on the one hand, would have acknowledged the right of the United States to capture and bring to adjudication before an American prize court every English ship employed in the service of the Confederation.

On the other hand, she would, once for all, before the eyes of the whole world, have practically resigned a claim which she was not brought to desist from either in the peace of Ghent, in 1814, or the transactions carried on between Lord Ashburton and Secretary Webster in 1842.The question then comes to this: Do you prefer to turn the "untoward event" to your own account, or, blinded by the passions of the moment, turn it to the account of your foes at home and abroad?

Since this day week, when I sent you my last letter, British consols have again lowered, the decline, compared with last Friday, amounting to 2 per cent, the present prices being 89 3/4 to 7/8 for money and 90 to 1/8 for the new account on the 9th of January. This quotation corresponds to the quotation of the British consols during the first two years of the Anglo-Russian war. This decline is altogether due to the warlike interpretation put upon the American papers conveyed by the last mail, to the exacerbating tone of the London press, whose moderation of two days' standing was but a feint, ordered by Palmerston, to the dispatch of troops for Canada, to the proclamation forbidding the export of arms and materials for gunpowder, and lastly, to the daily ostentatious statements concerning the formidable preparations for war in the docks and maritime arsenals.

Of one thing you may be sure, Palmerston wants a legal pretext for a war with the United States, but meets in the Cabinet councils with a most determinate opposition on the part of Messrs. Gladstone and Milner Gibson, and, to a less degree, of Sir Cornewall Lewis. "The noble viscount" is backed by Russell, an abject tool in his hands, and the whole Whig Coterie.

If the Washington Cabinet should furnish the desired pretext, the present Cabinet will be sprung, to be supplanted by a Tory Administration. The preliminary steps for such a change of scenery have been already settled between Palmerston and Disraeli. Hence the furious war-cry of The Morning Herald and The Standard , those hungry wolves howling at the prospect of the long-missed crumbs from the public almoner.

Palmerston's designs may be shown up by calling into memory a few facts.