Mr. Samuel L. Clemens, who is known to many of us, and ought to be known to all of us, as Mark Twain, was one of the passengers on the Quaker City when she took her ill-assorted party of excursionists to Europe and the East, and he has just given us, in a thick book of more than six hundred pages, a record of the tour. It might better have been a thinner book, for there is some dead wood in it, as there has to be in all books which are sold by book-agents and are not to be bought in stores. The rural-district reader likes to see that he has got his money's worth even more than he likes wood-engravings. At least, such is the faith in Hartford; and no man ever saw a book-agent with a small volume in his hand.

But if some of the book is needless, none of it is really poor, and much of it very good. Mr. Clemens's plan of delivering an unvarnished tale, of giving just his own impressions of what he saw, at once made his work sure of some real value as well as much freshness, and his book is one to be commended merely as a book of travels. But, of course, the "American humor" is the great thing. It is not in the light of a traveller that one regards a gentleman who when during his wanderings in the Holy Land he comes upon the "tomb of Adam," which the monks exhibit, thus gives utterance to a natural burst of sentiment:

The tomb of Adam! How touching it was, here in a land of strangers, far away from home, and friends, and all who cared for me, thus to discover the grave of a blood relation. True, a distant one, but still a relation. The unerring instinct of nature thrilled its recognition. The fountain of my filial affection was stirred to its profoundest depths, and I gave way to tumultuous emotion. I leaned upon a pillar and burst into tears. I deem it no shame to have wept over the grave of my poor dead relative. Let him who would sneer at my emotion close this volume here, for he will find little to his taste in my journeyings through Holy Land. Noble old man--he did not live to see me--he did not live to see his child. And I--I--alas, I did not live to see him. Weighed down by sorrow and disappointment, he died before I was born--six thousand brief summers before I was born. But let us try to bear it with fortitude. Let us trust that he is better off where he is. Let us take comfort in the thought that his loss is our eternal gain.

All the prominent characteristics of our peculiar school of humorists -- their audacity, their extravagance and exaggeration -- Mr. Clemens displays in fulness in the course of his ramblings, and he has some merits which belong to his individual self, and which make him a very agreeable companion when he is at ease and natural -- which is not always; for as he pads so, we must make free to tell him, does he sometimes grimace, and is professionally a humorist as he was professionally a book-maker. It will be a just punishment for him to reflect that no doubt many a farmer will read all his jokes -- the good ones as well as these bad ones we are speaking to him about -- with profound gravity and unshaking belief in them as so much serious log-book.

There is, besides those we have mentioned, another characteristic of "American humor," which consists in a certain sort of what may be called fatuousness. When the man in the stage-coach, riding along with "the great moral showman" without knowing him, kept on telling him, "some of Artemus Ward's jokes," and at the end of each one of them punched his companion in the side and said, "What a damned fool the fellow is!" he was not the worst critic that Artemus ever had. Nearly all his jokes have in them a display of mental helplessness -- not to say imbecility -- a drifting along of the mind from one topic to another, suggested but not really connected, topic, and are largely dependent upon this for their humorous effect. The same thing may be seen -- though not nearly so unmixed nor so often -- in the efforts of Mr. Josh Billings. The humor in the Nasby Papers consists rather in Mr. Locke's conception of the low, "dough-face" Democrat than in anything strictly humorous that is said or done by him after he is made, and the Cross-roads pastor and postmaster gives no exhibition of the trait mentioned. But the author of The Innocents Abroad has some of it -- though something of what he has is acquired and imitative, we should say -- and may be taken to be rather more nearly Artemus Ward's successor in this line than either of the other humorists to whom we have referred.