dred cubic feet of fresh air an hour in order to secure him against the effects of an undue accumulation of carbonic-acid gas, the proportion of the gas admissible in a habitable apartment being from .03 to .06 per cent. by volume of the air. Dr. Parkes, who has given much attention to the subject of ventilation, more especially in hospitals, says: "I have measured the air passing out of barracks and hospital-wards, and found that, when twelve hundred or fourteen hundred cubic feet per head per hour only were given, the carbonic acid reached .7 .8 or 9 per one thousand volumes, and that more than two thousand cubic feet were necessary to keep the air pure to the senses." The observations of De Chaumont, Grassi, and Morin, "fail to agree in this respect," he says. In a ward in the London Fever Hospital, Dr. Sanky found, by careful experiment, that eight hundred cubic feet per hour for each person were insufficient to keep the air sweet. The experiments of French observers lead to the same conclusion. In providing ventilation for the hospital Lariboisiere, in 1856, means were adopted at considerable expense to provide fourteen hundred cubic feet of fresh air per hour for each person with results entirely unsatisfactory. A series of experiments, carefully conducted, demonstrated that a hospital-ward required five thousand two hundred and fifty cubic feet of air per hour for each adult. The hourly change of this very large amount of air could easily be effected, in the opinion of Pettenkofer, "by difference of temperature or mechanical currents, the extent being dependent upon the size of the openings, crevices of windows, doors, etc." The investigations instituted by that eminent observer "showed that with a difference of thirty-four degrees between the external and internal air of a room of eighteen hundred and ninety-five cubic feet capacity, the air was entirely renewed in one hour, and more rapidly with increased difference of temperature.† The supply of pure air in the homes, urban high * Practical Hygiene, p. 136, fourth edition. + Vide an interesting paper on this subject in Harper's Magazine, October, 1873. ways, and public buildings of mortals, is a subject for sanitary science to deal with; and we are happy to see physicians forgetting their elegant formulæ and cure-all specifics for the nobler purpose of settling the practical problems which it involves. These comprehend the science of ventilation, the details of which the limits of this paper forbid us to consider. We will only remark that the subject of ventilation has perplexed the brains of architects and medical savans since the time when science first revealed to poor plodding mortals its necessity. It seems, however, to be little nearer solution to-day than it was in the beginning. The ends to be achieved are evident enough to an intelligent ape; the means of effecting those ends have thus far defied the ingenuity of his most intelligent and accomplished descendant of the nineteenth century. Perhaps it is not too much to hope that the time is drawing near when some practical-minded genius will discover the means of uniting the practical with the ideal on this subject; so that man may possess the genial comforts of a home, or the pleasure of a social entertainment, without, at the same time, being deprived of the beneficence of those "solar showers" about which Steinmetz has written so eloquently, nor isolated altogether from the free, fresh air of heaven. Finally, we repeat that ventilation is a modern idea. Our grandfathers and grandmothers neither knew, desired, nor needed to know any thing on the subject. And why should they? Their immense, open fire-places, with the back-log fire in winter, obviated the necessity of taking thought about a fresh-air supply. Moreover, the function of respiration was unknown until the growth of modern chemistry but a century since. Meanwhile, man had been taught by a mistaken moral philosophy to despise his dependence upon Nature, and even now, in many circles, loudly vaunts his independence of material environments. Such is the force of education and native conceit, the long inculcation of the fallacious doctrines concerning his mystical origin, and the means of attaining his still more mystical destiny! One would suppose that a few hours of quiet reflection would be sufficient to convince any thinking individual that he is as much a creature of environment as the lord of the deep, the king of the forest, or of the air, and as dependent on Nature for his characteristics as the tint of the flower on the sunbeam, the growth of the leaf on carbonic acid, or the grasses that wave in the fields on light and moisture in the atmosphere. And him, who is devoid of reflection, the experience of pain and sorrow ought to bring to the same conclusion respecting his own dependence. And, surely, the pangs of bodily disease are not without a kindly beneficence when they inculcate the great truth of man's dependence on, and subjection to, powers superior to his own. He who has had a pneumonia, or a pleurisy, been arrested by gout, lumbago, arthritis, or palsy, choked with carbonic acid, or stricken with pestilence or paralysis, is easily persuaded to abdicate the self-assumed title of "lord of creation," and is content to be regarded as not only a little, but considerably lower than the angels, if not wholly as a "servant of Nature," willing to learn of her in all humility, and to modestly conform to such conditions and requirements of life and health as she may have wisely imposed upon him, until he recovers, at least. The dying monarch, who had ostentatiously affected to despise life and its providences, found at last a kingdom too small a price to pay for a breath of air. But it could not be had on any terms. So there comes a time in the life of us all when the lesson of physical humility, which we fail to learn by reflection and philosophy, is taught us by the inexorable necessities of pain, privation, and death. ART. IV.-History of the United States, from the Discovery of the American Continent. By GEORGE BANCROFT. Vol. x., 8vo., pp. 593. Boston: Little, Brown & Co. 1874. WHEN the first volume of this work appeared, in the year 1834, the "appreciative" reviewers, no doubt, anticipated that it might be some years before they would be called upon to eulogise the completed work; but, had any person at that time ventured to prophesy that the lapse of forty years would find the History, not only unfinished, but barely reaching the point at which the United States commenced its existence as an independent nation, the suggestion would probably have been scouted as preposterous. Yet here, in the year 1874, are we confronted with a tenth volume, which brings us no further than the recognition of American Independence at the close of the Revolution. Although the author has dropped from the title-page of the present volume the words "to the present time," which figured on those of the earlier issues, it is nowhere intimated that this is to be the conclusion. It, therefore, seems probable that the task of reviewing the History as a whole is to be reserved for future generations. That the history of a single nation, and that one of the youngest on the globe, should have already increased to such enormous proportions, appears at first incomprehensible; but, on the perusal of the performance before us, the mystery is explained. Mr. Bancroft possesses two qualities which in a historian are, to say the least, remarkable: Of these the first is a tendency to discursiveness. It becomes too evident, at an early period of the work, that our author is unable to resist the temptation of setting forth his views, at length, on every subject to which he has occasion to allude. A topic incidentally introduced will naturally suggest another, and having commenced by enlarging on a theme, perhaps not too remotely connected with the purport of his history, he is tempted to branch off afresh on another connected only with the subject last discussed. Thus, in course of time, he finds himself at such a distance from the road on which he set out, that his only practicable course is to retrace his steps and commence anew at his original point of departure. Of course, all the fine things that have been evolved in these various digressions he is not disposed to cut away; they are therefore allowed to re. remain as a proof of his volubility, and his pages are thus encumbered with heavy loads of extraneous matter which swell the book to its present enormous size. The other quality which has been instrumental in enlarging the dimensions of Mr. Bancroft's work, is that intense admiration for European politics and politicians, vulgarly called VOL. XXX.-NO. LIX. 6 toadyism. That the history, and even the politics, of certain of the European powers were not without their influence on the rise and progress of the American nation is indisputable; and an inquiry into their condition would appear from time to time not inappropriate for the purpose of better elucidating the course of American affairs. Mr. Bancroft has therefore an excuse for introducing these subjects occasionally into his work; but this privilege he has abused ad nauseam. Not content with a brief and general statement of the condition of affairs in any particular nation at a given time, he has thought it necessary to investigate the very penetralia of every foreign government, to set forth the rise and progress of its views, civil and religious, and to account on philosophical principles for its every peculiarity! In other words, he aspires to write a Universal History, or, at least, a History of Universal Christendom. A notable instance of this proclivity of Mr. Bancroft's mind appears in the second chapter of the present volume, which is devoted to Germany. Our readers are aware that the only part which Germany took in the war of American Independence was the sending of Hessian mercenaries to devastate American soil, a course which would not, at first sight, appear to entitle her to a prominent place in a work devoted, at least nominally, to the United States. Yet our author has given us a résumé of the history of the Germans, from their earliest emigration from Central Asia through their European conquests-among which, by the way, he includes Gaul and Britain; forgetting that, although Gaul was conquered by and received the name of France from the Franks, and Britain, in like manner, the name of England from the Angles, and, although the Franks and Angles were originally German tribes, still neither France nor England ever formed any part of the German confederation, nor, for more than ten centuries past, has their history had any essential connection with Germany. We are then entertained (?) with the German wars with Rome; with the conversion of the Germans to Christianity; with the victories of |