We hear from pretty good authority that the Honorable Miss MURRAY, the distinguished English lady who has been traveling in the United States for some months past, is preparing a book of observations and criticisms upon our people and institutions;—and that she intends to vindicate the institution of slavery from the alleged misrepresentations of Uncle Tom's Cabin. Unless we have been entirely misinformed, Miss MURRAY has come to the conclusion, as a result of her personal observation, that the social institutions of the Southern States are decidedly in advance of those of any other portion of this country:—that a higher degree of culture and refinement is to be found there than elsewhere in the Union:—that Slavery is a blessing rather than a curse to the negroes themselves, and that the pictures of its cruelties and atrocities, given by Mrs. STOWE in her celebrated novel, are either very gross exaggerations, or so exceptional as not at all to be taken into the account, when forming a judgment of the institution itself. She will make this a prominent feature of her forthcoming book, and designs, we understand, to enter upon a special refutation of the views and representations of Mrs. STOWE. . . .

  Miss MURRAY's book, and especially that part of it which relates to this subject, will undoubtedly make a sensation in this country as well as in England. She is a lady of very decided intellectual ability, of great accomplishments, and holding a position in English society which will secure for her opinions on such a subject the greatest consideration and respect. Mrs. STOWE will undoubtedly find it necessary to make some reply,—and we are, therefore, likely to have a brisk and exciting warfare on this controversial subject.