Of all human writings, letters have been preserved in the smallest proportion. How few of those which the best-informed actors in great events or revolutions must have written, have been copied by elder historians or biographers! Such documents are, by their nature, at once the least accessible and the most liable to destruction; private interests, feelings, and fears, keep watch against their publication; but even when these were taken out of the way, it is to be feared that the narrow-minded habit of overlooking all their wisdom deemed minute, which has made the chronicles of nations so scanty, and many a life in two volumes such dull reading, also induced learned compilers to neglect, as beneath their search, the old letters bundled up in dusty chest or corner, till they served a succeeding generation for waste paper. Such mistakes have occasioned heavy losses to literature. Time leaves no witnesses in the matters of history and character equal to these. How many a disputed tale, on which party controversy has raged, and laborious volumes have been written, would the preservation of one authentic note have set at rest forever? The practical learning of our times, in its search after confirmation and detail, amply recognizes the importance of old letters; and good service has been done to both history and moral philosophy by those who have given them to the press from state-paper office and family bureau. In such collections one sees the world's talked-of-and-storied people as they were in private business, in social relations, and in what might be justly designated the status of their souls. In spite of the proverbial truisms, that paper never refuses ink, and falsehood can be written as well as spoken, the correspondence of every man contains an actual portrait of the writer's mind, visible through a thousand disguises, and bearing the same relation to the inward man that a correct picture bears to the living face; without change or motion, indeed, but telling the beholder of both, and indicating what direction they are likely to take. The sayings of wits and the doing of oddities long survive them in the memory of their generation--the actions of public men live in history, and the genius of authors in their works; but in every case the individual, him or herself, lives in letters. One who carried this idea still farther, once called letter-writing the Daguerreotype of mind--ever leaving on the paper its true likeness, according to the light in which it stands for the time; and he added, like the sun's painting, apt to be most correct in the less pleasant lines and lineaments. Unluckily this mental portraiture, after the fashion of other matters, seems less perceptible to the most interested parties. Many an unconcerned reader can at this day trace in Swift's epistles the self-care and worship which neither Stella nor Vanessa could have seen without a change in their histories.