The opinions of the Marquis on Mediterranean politics are worth regarding, because he has had much political experience in the highest ranks of foreign life--because from that experience he is enabled to give the opinions of many men of high name and living influence, and because he is an honest man, speaking sincerely, and speaking intelligibly. He regards the preservation of Turkey as the first principle of all English diplomacy in the east of Europe, and considers our successive attempts to make a Greek kingdom, and our sufferance of an Egyptian dynasty, as sins against the common peace of the world. Thus, within a few years, Greece has been taken away; Egypt has not merely been taken away, but rendered dangerous to the Porte; the great Danubian provinces, Moldavia and Wallachia, have been taken away, and thus Russia has been brought to the banks of the Danube. Servia, a vast and powerful province, has followed, and is now more Russian than Turkish; and while those limbs have been torn from the great trunk, and that trunk is still bleeding from the wounds of the late war, it is forced to more exhausting efforts, the less power it retains. But, with respect to Russia, he does not look upon her force and her ambition with the alarm generally entertained of that encroaching and immense power. He even thinks that, even if she possessed Constantinople, she could not long retain it. As all this is future, and of course conjectural, we may legitimately express our doubts of any authority on the subject. That Russia does not think with the Marquis is evident, for all her real movements for the last fifty years have been but preliminaries to the seizure of Turkey. Her exhibitions in all other quarters have been mere disguises. She at one time displays a large fleet in the Baltic, or at another sends an army across Tartary; but she never attempts any thing with either, except the excitement of alarm. But it is in the direction of Turkey that all the solid advances are made. There she always finishes her hostility by making some solid acquisition. She is now carrying on a wasteful war in the Caucasus; its difficulty has probably surprised herself, but she still carries it on; and let the loss of life and the expenditure of money be what they will, she will think them well encountered if they end in giving her the full possession of the northern road into Asia Minor. Russia, in possession of Constantinople, would have the power of inflicting dreadful injuries on Europe. If she possessed a responsible government, her ambition might be restrained by public opinion; or the necessity of appealing to the national representatives for money--of all checks on war the most powerful, and in fact the grand operative check, at this moment, on the most restless of European governments, France. But with her whole power, her revenues, and her military means completely at the disposal of a single mind, her movements, for either good or evil, are wholly dependent on the caprice, the ambition, or the absurdity of the individual on the throne. The idea that Russia would weaken her power by the possession of Constantinople, seems to us utterly incapable of proof. She has been able to maintain her power at once on the Black Sea, seven hundred miles from her capital; on the Danube, at nearly the same distance, and on the Vistula, pressing on the Prussian frontier. In Constantinople she would have the most magnificent fortress in the world, the command of the head of the Mediterranean, Syria, and inevitably Egypt. By the Dardanelles, she would be wholly inaccessible; for no fleet could pass, if the batteries on shore were well manned. The Black Sea would be simply her wet-dock, in which she might build ships while there was oak or iron in the north, and build them in complete security from all disturbance; for all the fleets of Europe could not reach them through the Bosphorus, even if they had forced the Dardanelles--that must be the operation of an army in the field. On the north, Russia is almost wholly invulnerable. The Czar might retreat until his pursuers perished of fatigue and hunger. The unquestionable result of the whole is, that Russia is the real terror of Europe. France is dangerous, and madly prone to hostilities; but France is open on every side, and experience shows that she never can resist the combined power of England and Germany. It is strong evidence of our position, that she has never _ultimately_ triumphed in any war against England; and the experience of the last war, which showed her, with all the advantages of her great military chief, her whole population thrown into the current of war, and her banner followed by vassal kings, only the more consummately overthrown, should be a lesson to her for all ages.