Wherever you find a man down there who believes in one of these theories you may turn to the next man and frame your talk upon the hypothesis that he does not believe in that theory; and after you have had experience, you do not take this course doubtfully, or hesitatingly, but with the confidence of a dying murderer—­converted one, I mean.  For you will have come to know, with a deep and restful certainty, that you are not going to meet two people sick of the same theory, one right after the other.  No, there will always be one or two with the other diseases along between.  And as you proceed, you will find out one or two other things.  You will find out that there is no distemper of the lot but is contagious; and you cannot go where it is without catching it.  You may vaccinate yourself with deterrent facts as much as you please—­it will do no good; it will seem to ‘take,’ but it doesn’t; the moment you rub against any one of those theorists, make up your mind that it is time to hang out your yellow flag.

Yes, you are his sure victim:  yet his work is not all to your hurt—­ only part of it; for he is like your family physician, who comes and cures the mumps, and leaves the scarlet-fever behind.  If your man is a Lake-Borgne-relief theorist, for instance, he will exhale a cloud of deadly facts and statistics which will lay you out with that disease, sure; but at the same time he will cure you of any other of the five theories that may have previously got into your system.

I have had all the five; and had them ‘bad;’ but ask me not, in mournful numbers, which one racked me hardest, or which one numbered the biggest sick list, for I do not know.  In truth, no one can answer the latter question.  Mississippi Improvement is a mighty topic, down yonder.  Every man on the river banks, south of Cairo, talks about it every day, during such moments as he is able to spare from talking about the war; and each of the several chief theories has its host of zealous partisans; but, as I have said, it is not possible to determine which cause numbers the most recruits.

All were agreed upon one point, however:  if Congress would make a sufficient appropriation, a colossal benefit would result.  Very well; since then the appropriation has been made—­possibly a sufficient one, certainly not too large a one.  Let us hope that the prophecy will be amply fulfilled.

One thing will be easily granted by the reader; that an opinion from Mr. Edward Atkinson, upon any vast national commercial matter, comes as near ranking as authority, as can the opinion of any individual in the Union.  What he has to say about Mississippi River Improvement will be found in the Appendix.{footnote [See Appendix B.]}

Sometimes, half a dozen figures will reveal, as with a lightning-flash, the importance of a subject which ten thousand labored words, with the same purpose in view, had left at last but dim and uncertain.  Here is a case of the sort—­paragraph from the ’Cincinnati Commercial’—­