Sir,--The letter signed "M." in your issue of this morning contains, I think, some statements which ought not to pass uncorrected. A "blockade" is, of course, the denial by a naval squadron of access for vessels to a defined portion of the coasts of a given nation. A "pacific blockade" is one of the various methods--generically described as "reprisals," such as "embargo," or seizure of ships on the high seas--by which, without resort to war, pressure, topographically or otherwise limited in extent, may be put upon an offending State. The need for pressure of any kind is, of course, regrettable, the only question being whether such limited pressure be not more humane to the nation which experiences it, and less distasteful to the nation which exercises it, than is the letting loose of the limitless calamities of war. The opinion of statesmen and jurists upon this point has undergone a change, and this because the practice known as "pacific blockade" has itself changed. The practice, which is comparatively modern, dating only from 1827, was at first directed against ships under all flags, and ships arrested for breach of a pacific blockade were at one time confiscated, as they would have been in time of war. It has been purged of these defects as the result of discussions, diplomatic and scientific. As now understood, the blockade is enforced only against vessels belonging to the "quasi-enemy," and even such vessels, when arrested, are not confiscated, but merely detained till the blockade is raised. International law does not stand still; and having some acquaintance with Continental opinion on the topic under consideration, I read with amazement "M.'s" assertion that "the majority in number," "the most weighty in authority" of the writers on international law "have never failed to protest against such practices as indefensible in principle." The fact is that the objections made by, e.g. Lord Palmerston in 1846, and by several writers of textbooks, to pacific blockade, had reference to the abuses connected with the earlier stages of its development. As directed only against the ships of the "quasi-enemy," it has received the substantially unanimous approbation of the Institut de Droit International at Heidelberg in 1887, after a very interesting debate, in which the advocates of the practice were led by M. Perels, of the Prussian Admiralty, and its detractors by Professor Geffken. It is true that in an early edition of his work upon international law my lamented friend, Mr. Hall, did use the words attributed to him by "M.": "It is difficult to see how a pacific blockade is justifiable." But many things, notably Lord Granville's correspondence with France in 1884 and the blockade of the Greek coast in 1886, have occurred since those words were written. If "M." will turn to a later edition of the work in question he will see that Mr. Hall had completely altered his opinion on the subject, or rather that, having