The deplorable consequences of an early and hasty marriage, as portrayed in her own history, may serve as a useful beacon to rash youth in all ages to come. Her earnest plea on behalf of Personal Merit cannot fail to win its way to many hearts—at least in this Country, the foster-home of the plebeiance and of democracy. But to her concluding argument especially are attention and respect due. The investigations heretofore made in this Country and Europe have developed a frightful catalogue of diseases and deaths resulting from inter-marriages; and more recent examinations in the wards of Hospitals, in the Asylums for Feeble-minded Children, in Institutions for the Deaf and Dumb, and Blind, trace directly those monstrosities and defects of organization, in a preponderating number of cases, to marriages of this character. Whether her immediate example furnished any confirmation on this head, the meagre details of the whole affair, which have been permitted to be divulged, do not afford any certain information; that it has been so in other branches of her family, and that the dread of it was upon her own mind, is most apparent in her letter. Her authoritative and vehement invective against these internecine marriages, it cannot be doubted, will draw prominent attention to the subject; and on this account, and many others, some of which have been indicated, Mrs. Gurney’s Letter requires at least no “apology” for being made public. MRS. GURNEY’S APOLOGY. PARIS, _January_ —, 1860. DEAR E * * *: Your name has been always on my lips and in my heart, and you alone of all the world have never questioned me. I come to you again, E * * *, as I have so often—as I did when we were children, when you folded me trustfully in your arms—and say to you: I am as I was then; and I hear you say: Tell me nothing, for I believe you always, and there must be no questioning between us.