in all countries bordering round the Arctic | branch of the inquiry denoted by the special Circle, should nowhere exist in the Southern term of Animal Physiology-the history of hemisphere. But how are we to explain the different families of fish, found by Agassiz in each of the great fresh-water lakes of North America, connected as they are by a common river? or how the fishes peculiar to the Ohio and many other rivers? or the species limited in existence to some of our own lakes? Or why should we find in some mountain pools near Killarney a molluscous animal not known elsewhere in the world. those organs and functions through which vitality receives and maintains its individual existence. This subject, in truth, is too vast in outline as well as details, and the discussions it embraces too various and important, to be dealt with in any single article, even exclusively thus directed. The functions of nutrition and assimilation,-of circulation and respiration,-of secretion and excretion,-and of the nervous system in its many parts-all these have been the objects of refined experiment and sedulous observation by the physiologists and physicians of our day; and with results which give a new face and form to this branch of science. But while putting aside the subject generally (or it may be reserving it for some future occasion), there is one class of the functions just named which we cannot wholly omit when treating of physical science Such instances, which might be endlessly multiplied, show how curious are the problems belonging to this part of natural history; and how perplexed in every part by the doubt of what may belong to a primitive geographical distribution of created beings-what to the revolutions of the surface of the globe, paroxysmal or gradual, which have since intervened. The argument for the former, supported as it is by the complete analogy of veg-in its relation to vital phenomena. We mean etable life, is too strong not to compel belief; though leaving it doubtful to what extent the limitations of localities and species originally existed. Further research may do something towards clearing away these doubts, but can never wholly remove them. The unquestionable changes in climate, and other physical conditions essential to life, from geological revolutions of the earth's surface; and the mighty influence of man, when he became a tenant of the globe, in multiplying, destroying, or transplanting, whatever of the living creation existed around him, have removed many of the marks or outlines which might have denoted this primitive distribution. Fossil geology to a certain extent comes in aid of the research; though in solving some questions it evokes others not less difficult. In the vast periods of time through which it carries us, we see the same revolutions of surface, elevations, depressions, and changes of land and sea; but the further we recede from our own time into these depths of ages, the more entirely do we lose all analogies of geographical distribution. "Even in some of our most recent strata," as Professor Owen remarks, "fossils occur for which we must seek the representatives in America; and to match the mammalian remains from Oolite, we must bring specimens from the Antipodes," In treating of these various questions, which have relation to Life as the subject of modern science, we have only partially alluded to that those wonderful functions which are fulfilled through the instrumentality of the nervous system, and which we cannot err in describing as of far higher interest than any others of the animal economy; seeing that they connect the conscious being, whatever its grade in creation, with every part of its own organization and with the world without. Sensations in all their forms, volitions in all their acts, find transmission solely through this portion of structure ;-one so little intelligible to the eye or outward observation, that not a single anatomist or philosopher of antiquity placed a right interpretation on its nature and uses. Modern science has encountered the subject with the better appliances of experimental inquiry and sound induction; and though much remains to be done, and much more may be deemed wholly unattainable, yet we can safely affirm that some of its greatest achievements are to be found in the anatomy and physiology of the nervous system. Into the details of these discoveries we cannot enter. They relate chiefly to that organization and distribution of nervous matter (including the Brain as an integral portion of it) through which the power is generated and transmitted in fulfilment of the various functions of life: and, yet further, to the especial relation between the several parts of the nervous system and their different functions; whether such as appertain to animal life appropriately, or those more purely of organic kind. This latter distinction in itself may be Scarcely can we name a function of life which deemed a recent discovery, and one prolific in does not include the fact of a power applied curious and instructive results; as, in truth, to it, thus varying in degree. Whether we are all those relations which connect particu- can apply the term intensity, as separate lar parts of the nervous structure with the from quantity, is more doubtful; for though offices they fulfil. Every step in these re- the distinction is valid, as applied to electrical searches opens out new views to the specula- action, we have no sufficient evidence to give tive eye, and offers new problems for experi- it the force of an argument here. A much ment and reason to resolve. The successive more cogent presumption to our purpose is and successful labors of Bichat, Bell, Magendie, and other eminent physiologists, thus directed, have been more recently extended and surpassed by those of Brown Sequard; to whose subtle powers of anatomical inquiry, still actively employed, we owe some of the most interesting discoveries in this part of animal physiology. Among these various topics, there is one question so closely allied to some we have been discussing, that it cannot fitly be put aside. Is there any special physical agent, acting in and through the nervous system, and by such action giving fulfiment to its numerous offices in the living economy? Or must we look to some mysterious power existing here, apart from matter and the forces acting on matter, as needful to explain the phenomena, and particularly those which connect the nervous system with consciousness and the mental functions? This question, like the analogous one as to a Vital Principle, presses upon us almost as a necessity of thought. As in so many other cases, language has sought to evade the difficulty of solution by phrases more or less convenient for use, but which indicate no new or real knowledge acquired. We have the terms of nervous power, principle, energy, and element, nerve force, innervation, etc.; all preferable, doubtless, to the older phrase of nervous fluid; but preferable simply because less definite in their meaning and assumption. To the question stated above, science has yet rendered no certain answer; but there are several presumptions favoring the view that some physical agent-analogous to, if not the same as, the natural forces of which we have so often spoken-does directly minister to the functions of the nervous system. One of these presumptions is founded on that conception of quantity, which is forced upon us in every consideration of nervous power, and is expressed equally by excess or deficiency in amount. We exhaust energy by action; we augment it again by time and rest. that furnished by time as an element in action through nerves. This very interesting fact of a rate of motion, already conjectured and vaguely estimated, has been recently attested by the beautiful experiments of Helmholz on the crural nerves of the frog, giving the result of a space of somewhat more than eighty feet passed through in a second of time. To subsequent observations of M. Helmholz we owe the further remarkable facts that the rate of motion of the nervous power in Man is about two hundred feet in a second, or more than double that observed in the frog; and that it sensibly augments with any augmentation of animal temperature. These experiments are so delicate in apparatus and manipulation, that few can undertake them; but their principle is one which in skilful hands may hereafter illustrate some of those variations and anomalies of nervous power which at present perplex all our reasoning. Meanwhile the fact ascertained of the propagation of power in definite time, brings us at once to the conception of a physical force, like those which act on matter through its molecular structure elsewhere in the natural world. And this presumption is strongly enforced when we come to consider the actual and intimate relation of these forces, and of electricity especially, to the functions and phenomena of the nervous system. At this point, however, a serious doubt suggests itself. Can these functions, so diverse in nature and quality as well as in degree, be due to any single agent of motion and power? Can we possibly predicate unity of any proximate cause, in actions which combine the functions of the several senses; voluntary and involuntary muscular contractions; the nervous influence directed to the various secret *This consideration of quantity, as an element of the nervous force-expressed both by excess and deficiency, in health and in disease has not, we think, been sufficiently regarded by physiologists or medical writers. We find it explicitly discussed by Sir H. Holland, in a chapter of his volume on Mental Physiology. ing organs; and the sympathies between differ- | with the conclusions drawn from other beautient organs, which John Hunter well describes ful experiments of Du Bois Reymond, on the as the "internuncial office" of the nervous system? This question will be at once seen as of great, perhaps insuperable, difficulty. As we cannot multiply agents to meet the many conditions just stated, or find adequate explanation of them in any structural differences of the conducting nerves, we can only approach a solution by looking to the diversities of organization upon which the nervous force acts; and by presuming, as indeed we are compelled to do, that these diversities are often of a nature to evade the most subtle research. The chemist and the microscope have disclosed to us many marvellous secrets of molecular aggregation; but they have rarely, if ever, been able to tell us of that ultimate structure, which at once defines and fulfils the various functions of life. We have spoken of Electricity as the physical power most nearly allied, as far as we yet know, to that acting through the nervous system. We are not propounding here one of the many vague hypotheses to which electricity, from its striking and complex phenomena, has given birth; but what is a legitimate inference from the most exact and delicate experiments. These, while leaving the fact of identity still unproved, and many collateral questions yet unresolved, have nevertheless disclosed such analogies and intimate relations, as to make it probable that the forces in question are at least mutually convertible, in the sense we have already given to this phrase. Had we space for it, we might relate some of those wonderful results derived from the experiments of Du Bois Reymond and Matteucci, which most especially favor this interpretation. We may merely mention, as being perhaps more cogent in its conclusions than any other, the experiment we have ourselves seen; where a simple but sudden and forcible contraction, by will, of the muscles of the fore-arm, evolves a current of electricity capable of passing through two or three miles of a helix coil, and thereby creating power enough to deflect the needle of a delicate galvanometer 50° or 60° or 70°, according to the vigor of the muscular contraction. The inference here seems direct and decisive; and it corresponds direction of the electrical currents pervading all muscular fibres, so uniform in character as to assume at once the conditions of a new law. Yet we are still short of that certainty which science is rigid in requiring. We have reason to believe all muscular action—perhaps every vital action-to be attended with some chemical change in the parts concerned; and every chemical change, as we know, produces disturbance of the electrical equilibrium. Changes of temperature, moreover, or molecular motions, each incidental to muscular contraction, may be concerned in evolving these electrical currents. But whatever are the ambiguities of this question, it is obvious that they all lie within that single circle which comprehends and connects the great Correlated Physical Forces of the universe ;—a magical circle, we may well call it, since it comprises within itself some of the most profound and mysterious problems which human reason can venture to approach. We must here come to a close; although there are still many topics which we might bring before our readers, illustrating the efforts and results of modern science in relation to this great subject of Life on the earth. It will have been noticed how often the question of Final Causes comes before us, as a consequence, and even integral part, of these inquiries. We have already alluded to this point; but cannot conclude without reverting once more to a principle of reasoning which it is of signal importance should be rightly appreciated in the interpretations it affords. A misplaced sophistry, fortifying itself by a single phrase of Lord Bacon's of doubtful meaning, has sought to impugn this method, and the conclusions thence derived. It cannot be done. Such reasoning is an integral necessity of our mental constitution. The fallacy lies here, as so often elsewhere, in imputing to the use of the faculty what belongs to abuse; since, if using that caution which the nature of the subject inculcates, we may safely and profitably employ it as a guide in research, as well as an exponent of discovery, in every part of the great domain of created life. From The Literary Gazette. Recollections of my Literary Life. By pres pro Crime, Education, and the Dwellings of the Poor, are both sadly serious phases of the same thing; but both are real in their way, only the one washes off all the dirt with scented soap, or throws away the work-a-day rags for the Sunday best, and the other puts the fact of a possible washtub out of sight altogether, and does not allow that the clothespress holds any holiday suit at all. Still, we repeat it Miss Mitford's rustics are human and English; and we are thankful for the loving charity that sketched them in such gentle What her earliest friendliness of mood. MISS MITFORD will always hold her rank as one of the most pleasant and elegant writers of a passing school. In her time literature was more dilettante than it is at ent, and authors had fewer missions, fewer specialities, less earnestness, and no thought of a vocation. They wrote, in general, more because authorship was held to be a graceful kind of accomplishment, than because their souls were oppressed with thoughts that demanded utterance, or because they held doc- work was to portraiture and story, that is her trines which it seemed to them to be their latest-"Recollections of my Literary Life" life's first duty to promulgate. They were -to literary gossip. One can easily trace still under the smooth influence of Addison the same hand and the same mind in both, and his time; thinking more of the manner though the subjects have nothing whatever than the matter, and supremely careful of in common, and so many years have swept prieties of diction and the harmonious flow between the two productions. The present of concluding periods. They had neither the volume is a new edition; adorned with a porruggedness nor the strength, neither the bold trait of the kind, mild, thoughtful face, with assertion nor the human advocacy of their lit- the clear, large eyes and benevolent but erary successors. They sought to please, nct somewhat sad mouth, that all who knew her to preach-to win admiration for their "Recollections of will so easily recognize. grace, not adherence to their cause. But they an- my Literary Life" is simply a collection of swered, and answer still, to a certain need of papers or essays; now telling of some jourthe mind; and will always find readers and ney, and gossiping pleasantly on all the admirers; giving as they do, much pure great names and associations connected with intellectual beauty, and many sweet and the locality; now criticizing some poet with graceful fancies. The mistake was in sup-generous extracts from the most popular and posing such literature to be the living literature of a nation, or in believing that man could live on pretty fancies only, with nothing more solid than a fresh rural syllabub, or a chaste whipped cream. Miss Mitford's first book was that most charming idyll," Our Village," where the scent of the fresh-mown hay lingers on every page, and where the men and women are living rustics, yet with the idealizing sheen of the summer sun upon them. There are no Corydons or Strephons in "Our Village," no operatic shepherdesses with Swiss hats all on one side, no life of Arcadian love and innocence, to fret our sense of truth and to belie our own experience. They are actual human beings, and may be met with in any well-taught hamlet of the country; but it must be confessed that they always wear their Sunday clothes, and are forever on their best behaviour. Dear Miss Mitford's gentle heart and feminine hand could never have probed or traced the coarser truths of rural life. "Our Village" and the Government Blue-books on the least known alike. These extracts are always well chosen and full of grace; bound together by a running commentary of genial praise, and altogether forming a most charming handy book of beautiful thoughts. Several stories, not generally known, are cast in; as that terrible murder of Sir John Goodere by his brother, the Captain of the Ruby, both uncles of Foote: and there are hosts of happy reminiscences of her own young life—of her bright-natured father whose spoiled darling she was, and of the gentler, graver mother whose memory passed into a kind of family saint, canonized by love and admiration. Then, there are a few kindly words and discriminating praises for any young author that came within the limited sphere of her later life: and she is forward in pointing out the power and genius of American writers. She was intimate with some of our first men: with some who were in their zenith when she was still callow and unformed, and with others on whom the light of early manhood had just begun to shine when the shadows of night were stealing over her. She had, too, rather | won a lottery prize of twenty thousand pounds. a wide acquaintance among the "unrecog- In a few years the only representative of that nized" of literature; the men with their one prize was a Wedgwood dinner service which poem, the women with their one tale; which Mr. Mitford gave her to commemorate the every one in a certain section knows by heart, event. In later years Miss Mitford supbut no one out of that section has ever heard ported and tended her father with most heof. It is extraordinary how many such there roic love and förtitude: and of all the good are clinging to the skirts of the literary world that may be said of her, in nothing does her of whom it is devoutly believed that they might character shine more highly than in her woif they would, sway the destinies of empires, manly devotedness to the life which should but who are silent from wisdom, and whose have cared for and supported hers. Looked inaction is the god-like repose of strength. at from this point of view, Miss Mitford was Many of these are gathered into her "Recol-out of the sphere of ordinary criticism. lections," and chronicled amongst those whom It is impossible to give any clear account of she most admires; and it must be confessed that generally she justifies her praises by her quotations; for all that authors and book are perhaps equally unknown to the public. Calm and uneventful as was Miss Mitford's outer life, she did not escape her full share of trials. Her mother was an heiress, ten years older than her father, and possessed of twenty-eight thousand pounds, besides certain landed property. Two hundred a year only was settled on herself. Her husband ran through the rest in course of time; alienated a rich cousin who had made her his heir; abandoned a field of practice just as it was becoming lucrative, and, in fine, wrought for his own overthrow as diligently as good-present form; for few names breathe more delicate perception of grace and beauty, or natured, reckless, expensive men so often do. are associated with pleasanter memories of He had a chance of redemption given him. womanly heroism and love, than that of When Mary was a little girl of ten years old she Mary Russell Mitford. this present work. As she herself says in the preface-it is "desultory and wayward," with "far too much of personal gossip and of local scene-painting for the grave pretension of critical essays, and far too much of criticism and extract for any thing approaching in the slightest degree to a autobiography." It is a charming, disconnected series of independent sketches; one of those books without beginning, middle, or end, which you may read for a day or for an hour, at your will; open it where you like, and leave off where you like; always sure to find "your place" again; or something that will do quite We are glad to see it re-issued in its as well. WIFE AND WOLF.-In France, the Society ALTHOUGH not strictly what the Spectator for the Protection of Animals does not enjoy has usually understood by "Publications," it that popular respect which it deserves; the small may be mentioned that a new journal is started wits of the capital indulging in endless jokes at in Paris, under the title of Le Memorial Diplo its expense. The last joke is to this effect :- matique. It originates in the opinion (which A countryman, armed with an immense club, some Englishmen may dissent from) that sepresents himself before the president of the soci- crecy in diplomacy has passed away, and that ety, and claims the first prize. He is asked to now "les gouvernements négocient au grand to describe the act of humanity on which he jour." Therefore the originators of Le Memorial founds his claim. "I saved the life of a wolf," propose to devote themselves specially "a l'etude replies the countryman: "I might easily have des questions internationales," on the basis of killed him with this bludgeon," and he swings the treaty of Paris, as superseding the Holy Alhis weapon in the air, to the intense discomfort liance, and in the interests of peace and progof the president. "But where was this wolf?" ress. Papers and correspondence on diploinquires the latter, "what had he done to you?"matic subjects will not, however, constitute the "He had just devoured my wife," is the reply. sole topics of the new journal. Literary, theatThe president reflects an instant, and then says, rical, social, industrial, and financial questions "My friend, I am of opinion that you have been will be noticed.-Spectator, sufficiently rewarded." |