This is a goodly volume, of nearly six hundred pages; and if mirth is indeed one of the best of medicines, as we have somewhere read--we think in Hall's Journal of Health, an unimpeachable authority--Roughing It should have a place in every sick-room, and be the invalid's cherished companion. In taking Mr. Clemens' jokes, however, for hygenic purposes, it behooves the patient to exercise great caution in regard to the strength of the dose, if we may judge of the power of the medicine from its effects upon a hungry camel, which once, at the head-waters of the Jordan, made an experiment upon the author's overcoat as an article of diet. The overcoat was left lying upon the ground while the travelers were pitching their tents, and the camel, having contemplated it for a while with a critical eye, seemed to come to the conclusion that it must be a new edible. But we will let the author tell the story, in his own inimitable way:

He put his foot on it, and lifted one of the sleeves out with his teeth, and chewed and chewed at it, gradually taking it in, and all the while opening and closing his eyes in a kind of religious ecstasy, as if he had never tasted anything as good as an overcoat before, in his life. Then he smacked his lips once or twice, and reached after the other sleeve. Next he tried the velvet collar, and smiled a smile of such contentment that it was plain to see that he regarded that as the daintiest thing about an overcoat. The tails went next, along with some percussion caps and cough candy, and some fig-paste from Constantinople. And then my newspaper correspondence dropped out, and he took a chance in that--manuscript letters written for the home papers. But he was treading on dangerous ground, now. He began to come across solid wisdom in those documents that was rather weighty on his stomach; and occasionally he would take a joke that would shake him up till it loosened his teeth . . .

However, it was not our author's jokes, powerful as were their effects, but one of his statements of facts--one of the mildest and gentlest, he declares, that he ever laid before a trusting public--that proved fatal to the sensitive animal, and caused him to "fall over as stiff as a carpenter's work-bench, and die a death of indescribable agony."

This species of humor is certainly grotesque, and hardily extravagant. But it is also genuine, and thoroughly enjoyable. In the same vein, and finer still, is the sketch of the coyote, his appearance and characteristics, in which the writer has managed (as he often does) to convey an accurate and graphic picture, while apparently indulging--or rather rioting--in the drollest and most fantastic exaggeration. The episode of Mrs. Beazely and her son, or the Erikson and Greeley correspondence, which has been extensively reproduced in the newspapers, though based upon a well-worn theme, is set in such a quaint, half-pathetic frame-work of narrative as makes it quite fresh and ineffably comic. On almost every page of the volume this vein of broad, robust humor crops out. It is not fine and pensive, like Irving's. It is not artificial, or based upon any literary model, and does not depend for its effect upon elaboration or word-cobbling. Its specific character is its sturdy honesty and rugged sense, antagonistic to sentimentality and shams. The fun with which the volume overflows more copiously than any previous book of the author's, is not mere fun. It constantly does the work of satire, though in a spirit more genial than that of most satirists; and constantly evinces keen insight and shrewd observation. The preface contains a facetious apology for the cirumstance that the book embodies a good deal of information, especially concerning the rise, growth, and culmination of the silver-mining fever in Nevada. The apology is scarcely needed, for though the twenty-odd chapters which deal with that remarkable episode do, in fact, contain a vast amount of information, it is served up in such a style that the reader absorbs it without effect, and becomes unconsciously instructed, while dreaming only of entertainment--as students at German universities said to become learned in metaphysics, not by much "poring over miserable books," but by loquacious discussions, in hours of recreation, over their lager and meerschaums.

As Irving stands, without dispute, at the head of American classic humorists, so the precedence in the unclassical school must be conceded to Mark Twain. About him there is nothing classic, bookish, or conventional, any more than there is about a buffalo or a grizzly. His genius is characterized by the breadth, and ruggedness, and audacity of the West; and, wherever he was born, or wherever he may abide, the Great West claims him as her intellectual offspring. Artemus Ward, Doesticks, and Orpheus C. Kerr, who have been the favorite purveyors of mirth for the Eastern people, were timid navigators, who hugged the shore of plausibility, and would have trembled at the thought of launching out into the mid-ocean of wild, preposterous invention and sublime exaggeration, as Mark Twain does, in such episodes as Bemis' buffalo adventure, and "Riding the Avalanche," where, after picturing the unfortunate tourist as "riding into eternity on the back of a raging and tossing avalanche," he concludes with the remark, "This is all very well, but let us not be carried away by excitement, but ask calmly, how does this person feel about it in his cooler moments next day, with six or seven thousand feet of snow on the top of him?"

It would be a great misapprehension, however, to conceive of Roughing It as merely a book of grotesque humor and rollicking fun. It abounds in fresh description of natural scenery, some of which, especially in the overland stage-ride, are remarkably graphic and vigorous. The writer's talent for clear, impressive narrative, too, is illustrated in the chapters devoted to the terrible story of the desperado, Slade, which has as intense an interest as any thing in the wildest sensational novel of the day.

Of the three hundred wood-cuts that illustrate the volume we can say nothing complimentary, from an artistic point of view. But some of them are spirited, and many of them are suggestive. Crude as they are in design, and coarse in execution, they have afforded us much amusement; and the majority of readers would, we are sure, regret to dispense with them.