A mail bag is an epitome of human life. All the elements which go to form the happiness or misery of individuals—the raw material, so to speak, of human hopes and fears—here exist in a chaotic state. These elements are imprisoned, like the winds in the fabled cave of Æolus, "biding their time" to go forth and fulfil their office, whether it be to refresh and invigorate the drooping flower, or to bring destruction upon the proud and stately forest-king.

Well is it for the peace of mind of those who have in temporary charge these discordant forces, that they cannot trace the course of each missive as it passes from their hands. For although many hearts are made glad by these silent messengers, yet in every day's mail there is enough of sadness and misery, lying torpid like serpents, until warmed into venomous life by a glance of the eye, to cast a gloom over the spirits of any one who should know it all; and to add new emphasis to the words of the wise man, "He that increaseth knowledge, increaseth sorrow." But until they are released from their temporary captivity, the letters guard in grim silence their varied contents. Joy and sorrow as yet have no voice; vice and crime are yet concealed, running, like subterranean streams, from the mind which originated, to the mind which is to receive their influence. The mail bag is as great a leveller as the grave, and it is only by the superscription in either case, that one occupant can be distinguished from the other.

But leaving these general speculations, let us give more particular attention to the motley crowd "in durance vile." If each one possessed the power of uttering audibly the ideas which it contains, a confusion of tongues would ensue, worthy of the last stages of the tower of Babel, or of a Woman's Rights convention. Indeed matters would proceed within these leathern walls, very much as they do in the world at large. The portly, important "money letter," would look with contempt upon the modest little billet-doux, and the aristocratic, delicately-scented, heraldically-sealed epistle, would recoil from the touch of its roughly coated, wafer-secured neighbor, filled to the brim, perhaps, with affections as pure, or friendship as devoted as ever can be found under coverings more polished. Would that the good in one missive, might counteract the evil in another, for here is one filled with the overflowings of a mother's heart, conveying language of entreaty and remonstrance,—perhaps the traces of anxious tears,—to the unwary youth who is beginning to turn aside from the path of rectitude, and to look with wishful eyes upon forbidden ground. Need enough is there of this message to strengthen staggering resolution, to overpower the whispers of evil; for close by are the suggestions of a vicious companion, lying in wait to lure him on to vice, and to darken the light of love which hitherto has guided his steps.

In one all-embracing receptacle, the strife of politics is for a time unknown. Epistles of Whigs, Democrats, Pro and Anti-Slavery men lie calmly down together, like the lion and the lamb, (if indeed we can imagine anything lamb-like in political documents,) ready, however, to start up in their proper characters like Satan at the touch of Ithuriel's spear, and to frown defiance upon their late companions. Theological animosity, too, lies spell-bound. Orthodoxy and Heterodoxy. Old and New School, Protestant and Catholic, Free Thinkers and No Thinkers, are held in paper chains, and cease to lacerate one another with controverted points. Nor in this view of dormant pugnacity, should that important constituent, the Law, be left out of sight. An opinion clearly establishing the case of A. B. unsuspectingly reposes by the side of another utterly subverting it, thus placing, or about to place, the unfortunate A. B. in the condition of a wall mined by its assailants, and counter-mined by its defenders, quite sure (to use a familiar phrase,) of "bursting up" in either case. And the unconscious official who "distributes" these missiles, might well exclaim, if he knew the contents, "cry havoc, and let slip the dogs of war."

But we come to another discord in our miniature life-orchestra. Those all-embracing, ever-sounding tones, which lie at the two extremities of the "diapason of humanity," namely, Life and Death, here find their representatives. Here lies a sable-edged missive, speaking to the eye as the passing bell speaks to the ear, telling of blighted happiness, a desolate home, and loving hearts mourning and refusing to be comforted because the loved one is not; while close at hand and perchance overlying the sad messenger, is the announcement of another arrival upon the stage of life—Our First—and though it is as yet behind the curtain, not having made its bow to the world at large, is an important character in the green room; and the aid of that convenient individual, Uncle Sam, is invoked to convey the information of its advent to a circle of expectant friends, as highly favored as that select few who are sometimes invited to witness a private performance by some newly-arrived artist, before he makes his appearance in a more public manner.

Nor should we omit at least a passing notice of the humorous aspects of our Bag. Physiognomy will not go far in aiding us to determine as to a given letter, whether its contents are grave or gay. A well-ordered epistle, like a highly bred man, does not show on its face the emotions which it may contain. But in what we may call the lower class of letters, where nature is untrammeled by envelopes, and eccentricity or unskilfulness display themselves by the various shapes and styles in which the documents are folded and directed, there is more room for speculation on their internal character; and it is the author's intention to furnish some rare specimens of unconscious humor of this kind, for the delectation of his readers.

As we contemplate the wit, fun, humor, and jollity of all sorts, which lie dormant within these wrappages, we are tempted to retract our commiseration for the imaginary official whom we have supposed to know the contents of the letters in his charge, and therefore drag out a miserable existence under their depressing influence. At least we feel impelled to modify our remarks so far as to say that in the case supposed, his days would be passed in alternate cachinnations and sympathizing grief. He would become a storehouse of wit, a magazine of humor. For there is much of wit, humor, and jollity running through these secret channels, that never is diffused through the medium of the press, but flows among the privacies of domestic circles, adding life to their intercourse, and increasing the attractions of social fellowship, like some sparkling stream, both refreshing and adorning the landscape through which it takes its course.

We leave the further development of this prolific train of thought, to the reader's imagination. Yet the imagination can devise no combination more strange than those which may be found every day within the narrow precincts of which we have been speaking; and the same may be said of the Post-Office system at large, interwoven as it is with the whole social life of civilized man.

The laws of the land are intended not only to preserve the person and material property of every citizen sacred from intrusion, but to secure the privacy of his thoughts, so far as he sees fit to withhold them from others. Silence is as great a privilege as speech, and it is as important that every one should be able to maintain it whenever he pleases, as that he should be at liberty to utter his thoughts without restraint. Now the post-office undertakes to maintain this principle with regard to written communications as they are conveyed from one person to another through the mails. However unimportant the contents of a letter may be, the violation of its secrecy while it is in charge of the Post-Office Department, or even after having left its custody, becomes an offence of serious magnitude in the eye of the law; and as the quantity and importance of mail matter is continually increasing, it has been found necessary to adopt means for its security, which were not required in the earlier history of the Post-Office. One kind of danger to which the mails were exposed before the days of railroads and steamboats, namely, highway robbery, is now almost unknown. The principal danger at present to be apprehended, is from those connected with their transportation and delivery, and a system of surveillance has been adopted, suited to the exigency of the case, namely, the creation of Special Agents, who have become a fixed "institution," likely to be essential to the efficiency of the Department, as long as any of its employÉs are deficient in principle or honesty. The origin of this Special Agent System will be given elsewhere. It is sufficient to say here, that the curious developments of character, and combinations of circumstances, which will be found in the following pages, were mainly brought to light by the operation of this system, as carried out by one of its Agents. "Ten years" of experience have given the author (or at least ought to have given him) an ample supply of material for the illustration of nearly every phase in Post-Office life. His principal difficulty is the "embarras des richesses;" yet he has endeavored to select such cases as are not only interesting in themselves, but well calculated to benefit those for whose use the present work is especially designed.