919 Mephitic Gases in Mines-No. X. 920 fire the gas. As irons will only be heated would be absorbed thereby. In about when they are needed for immediate use, twenty-four hours after a portion of charand as they must be used immediately, or coal had been exposed in a mine, it would otherwise they will become cold, no diffi- become saturated with gas, and it would culty can arise in keeping them free from then be needful to send it out of the mine. coal dust and other combustibles, during the | But if it was plunged into cold water, there moment which intervenes between their it would give out a large portion of the gas being sent down the shaft, and the casting it had imbibed: it might then be thoroughly of liquid upon them. dried, but not in the open air, and afterwards sent down into the mine, where it would receive a fresh cargo of gas, and thus, from time to time, charcoal would become a vehicle wherein carbonic acid gas might be perpetually conveyed out of a mine, to the great ease and comfort of the miner. Fragments of wood, threads of silk, or even threads of linen, completely dry, exposed in a mine, then plunged into water at the head of the pit, afterwards dried, and again sent down into the mine, would act in a manner similar to charcoal, only in a less degree. If we visit the laundress in her apartment, we may take an useful lesson on this head. There we behold how a gentle and innoxious heat is produced and kept up, by a succession of iron heaters being placed within an iron box; and with what ease she deals with the finest muslin and lace, either with her box or Italian iron, and how uniformly she keeps up the heat by placing one iron in the fire while she cools another. Greater difficulty, however, lies in the way of the miner than in that of the laundress, because his fires must, of necessity, be more distant; but a certain mode once adopted, and uniformly acted upon, would, when needful, give almost as great facility to the miner in heating his irons as to the laundress; because the irons need not be heavy, and during the working hours in a mine, a continual communication is kept up between the bottom and the top of a pit or shaft. Steam itself, if only the mere vapour of water, has its effect upon hydrogen, because hydrogen has great affinity for caloric, greater indeed than for any other substance, and steam brings abundantly more caloric into contact with hydrogen than cold water; and this quantity of caloric, great as it is, introduced to hydrogen in the wet way, will not explode the inflammable gas, even where it exists in such abundance, that the mere flame of a lamp or candle would cause an explosion which would blow up the mine. Cold water, indeed, combines with hydrogen, in the small way, but hot water absorbs this gas plentifully; and if one-third the volume of steam be introduced into inflammable gas, this gas will not explode with flame. A shallow tin cup, containing a pint of water, placed upon a hot iron box, will boil in six minutes, and the water will all be converted into vapour in less than thirty minutes; and in like manner larger quantities. Charcoal in fragments will absorb carbonic acid gas more abundantly than in powder. If dry charcoal, therefore, in pieces about the size of a man's thumb, were placed in shallow troughs, in a dry situation, upon or near the floor of a mine infested with carbonic acid gas, or chokedamp, considerable quantities of this gas The sluggish inaction of this gas is often met by a correspondent inaction in the miner, who, as if unconscious of the growing danger, suffers this gas to accumulate until it becomes too formidable for his utmost efforts, when a careful and continual attention to preventives would often carry off the gas as it issued into the mine, and keep danger at a distance. However, so it is, and so we find it in every department of life: "A prudent man foreseeth the evil, and hideth himself; but the simple pass on, and are punished." Even the diligent and laborious man, whose industry and activity are proverbial, is equally careless of certain circumstances around him, with the most sluggish of mankind; nay, sometimes more so. For, with his industry and activity, like a twin brother, grows up adventure, or a spirit of adventurous indifference to difficulties; and although he by no means intends this in his sober moments, yet he seems to court the presence of danger rather than to shun it; waiting until a crisis arises, that he may overcome danger at once, rather than combat it in detail. In very extensive mines, where galleries of miles in length exist, it is much more difficult to apply these preventives or remedies than in small works; because the immense extent, and varied ramifications of these mines, call for such quantities of air to prevent the accumulation of gas, and such quantities of materials to act upon gas when accumulated, in order to disinfect the mine, that the owners and overseers of these extensive works are appalled at the very idea of supplying them. Such is the suffocating closeness of mines infested with inflammable gas, that the very idea of in the troducing steam alarms the miner; he connects heat and steam inseparably into one idea, and mixes up suffocation and distress so intimately therewith, that steam is as unpopular with the miner as inflammable gas. Lime, in its various applications, as well as chlorine and charcoal, may be introduced in the cold way, as already prescribed, perhaps with as much effect as in steam; and, therefore, no particular emphasis has been laid upon steam. Steam, however, would by no means be found so insupportably hot as many imagine; because the moisture, inseparable from steam, tempers the air in which it floats; for heat is latent in steam, and such portions of steam are as insensibly condensed by surrounding objects, yield an agreeable cooling moisture to the human frame. In extensive works, air-pits, air-stoves, or air-furnaces, are indispensable. The introduction of safety-lamps into these mines was never intended to supersede the necessity of air-pits and air-stoves; no, they were introduced as auxiliaries to supply their lack of service, at certain seasons, and in certain places; and prevent explosions of gas, and the consequent death of miners, when the ordinary ventilation of a mine failed. Such precisely is the nature of the remedies which are the object of these essays. An air-stove, or air-furnace, may be, and frequently is, of the following form; and it acts upon the head of an air-pit on the principle of rarefaction, as has been already described in a previous article. A conical building, like the furnaces of glass-works, is erected around the top of an air-pit, which air-pit is sunk upon an elevated portion of the stratum of coal then in a state of being worked. Three or four doors lined with cloth, usually bar the entrance of air from the atmosphere into this stove, and these are opened and shut in succession, when any person enters, in order to prevent a rush of atmospheric air. Fires are, or ought to be, kept perpetually burning in these stoves or furnaces; the effects of which are, as no air from the atmosphere can enter this building, to draw air up the pit from the works below. Both atmospheric and foul air or gas are by this means made to ascend from the works, upon the principle of rarefaction already noted; and this current is supplied by the air which descends down the shafts or pits sunk upon the deep portion of the stratum of coal for the purpose of working the same, which currents take up and bring with them into this furnace a large portion of the inflammable gas, afforded by the mine through 118.-X. which they pass. Finally, this contaminated air escapes into the atmosphere, with the smoke of the furnace itself, through an aperture above the head of the cone, which may be denominated its chimney. Accidents, such as the falling in of sundry parts of the mine, &c. neglect in omitting to open or shut certain doors in the galleries of the mine, which, turn the currents of air on or off in the various compartments thereof, &c. &c. a sudden rise of water up to the roof, in a wateror airgate, &c. with incidents almost innumerable, interrupt the regular currents of air, and suffer gas to accumulate, until the most imminent danger surrounds the miners; and some of these impediments require a considerable time to elapse, in the use of means by which the mine may be restored to a healthy state. But in these extensive mines, imminent danger seldom exists throughout the mine; this danger is generally in some one compartment, and frequently in one of no great extent; and this compartment, treated at that time in a proper manner, might be disinfected without any thing like an herculean labour or expense, if recourse were had to proper disinfectors in time. If a boy, or boys, or aged men, were appointed to attend to this very thing, the miners themselves would not fail to call the attention of those persons to those compartments of a mine where a danger existed, so soon as danger became apparent; and it is for this very time that safety lamps were invented, and the remedies which I have noted were, and are, especially intended: a blowing apparatus at such a time would be invaluable; it might save the lives of many miners, and avoid much damage. That there exists a direful necessity for something more than currents of air, and even safety lamps, excellent as they are, is notorious to the world. The frequent accounts which come forth to the public, of catastrophes, equal to, if not exceeding those which were witnessed in any age of the world, wherein multitudes of men, who are our brethren, are instantaneously hurled into eternity by explosions of inflammable gas in mines, leaving, all bereft and desolate, widows and orphans to bewail their untimely exit, and claim our humane exertions, are proofs which are written in blood; and these call for the united energies of the whole mass of human intellect to prescribe and apply a remedy; nothing ought to be left untried which is likely to mitigate, much less that which may eradicate, this a rming evil. Is there no balm in Gilead? Is there no 3 M 923 Structure of the Osseous System—Essay I. physician there? Why then is not the health of the daughter of my people recovered? These were questions which Jehovah asked, by the mouth of His prophet of old, in order to rouse from apathy the house of Israel; and may we not ask them anew, in respect of so large a portion of our brethren as the miners of Great Britain? Their cause is of equal importance, for men are men in every age and every department of mankind, and the bodies, as well as the souls of all, are precious in the sight of God. 924 upon their habits and modes of life; and even how the possession or absence of this elaborate framework is associated definitely and uniformly with the possession or absence of organs-here absolutely of the utmost importance there, as absolutely the contrary. There is another species of interest, which a subject of this nature is well calculated to excite, namely, that which is called forth by the close examination, of a beautiful proof and example of the wisdom and goodness of the great Eternal; and in contemplating the design, the elegance, and the admirable workmanship of the skeleton, either as a whole, or in its parts, the mind cannot but revert to Him, whose wisdom sketched, CHANISM OF THE OSSEOUS SYSTEM, (OR and whose power executed the plan, with SYSTEM OF THE BONES.) (To be continued.) ESSAYS ON THE STRUCTURE AND ME ESSAY I. THE Consideration of the osseous system is replete with attraction. Independently of the philosophical interest, which portions so important of the organized system must ever excite in the inquiring mind, we cannot behold these last relics of mortality, proclaiming that their animal life, with all its multiform energies and sensations, has once been, and view them struggling against the process of resolution into their last elements, and slowly yielding to the crumbling hand of Time, without a melancholy concern. Some one has called the world "one vast charnel house," and so with truth it is. Wherever we step, these admonitory fragments rivet our attention,-not only are they scattered over the surface of the globe, not only do the spade and the ploughshare perpetually turn them up, but if we institute an examination into lower strata of the earth, we are there presented with the bones of animals, whose races have passed away and become extinct-of whose names and habits the records of history give us no account, and of whose nature and conforma. tion these relics alone exist to speak. In a philosophical point of view, the structure and mechanism of the bones, which constitute at once the grand outline and groundwork of the animal fabric, must ever be an engaging subject. It is curious to observe how the first rudiments of osseous matter are deposited, and trace the subsequent process, till the bone has acquired its firmness and solidity. It is curious to see how calculated every bone is for its specific purpose, and how the whole skeleton harmonizes with itself; how the want of one bone implies the want of another, thereby forming a singular feature in the classification of the animal kingdom, and bearing gratitude and reverence. Many subjects produce interest; but unfortunately, every interesting subject does not leave the mind in a genuine healthful state. The interests, however, which we have hinted at, as arising from a contemplation of our present theme, are legitimate; they are connected with the improvement, the invigoration, and expansion of the mind; since the more we study in the page of nature, the more habituated shall we be to calm reflection-the more enabled to repress the turbulence of those passions which agitate the giddy throng, and the more pure and simple will be our pleasures and desires. To excite these interests, while at the same time information is afforded, the following Essays are arranged; and if the writer has failed, impute it alone to his unskilfulness. A superficial glance at the structure of animal bodies, enables us at once to ascertain that they are composed of solids and fluids; a combination which, it would seem, is essential to constitute an organized being, for to such a combination only is vitality superadded. This combination, as we have observed in a previous series of essays, essentially differs from that which occurs in crystallization, inasmuch as it is not dependent upon chemical laws; while inorganic bodies in general are merely penetrated with water, which mingles with their particles, without being at all a constituent necessarily in structure, or composition; but in organic bodies the union is vital and essential. The solids of the animal frame are arranged under two heads, namely, those whose texture is hard and compact, and those in which it is more soft and yielding; the former including the bones and cartilages; the latter, the muscles, vessels, nerves, and various membranes of the body. The bones of the animal frame in their natural arrangement and projection, are collectively termed the skeleton, (from the Greek aria, which signifies to make dry, to deprive of moisture.) The skeleton serves as the framework of the body-a support to the whole, and as a defence to organs immediately necessary for the preservation of life. To the skeleton are attached the muscles, or moving agents of the body, and the separate bones composing it may be considered as levers, upon which these powers exert themselves. The structure, the uses, and the union of these bones, will form the subject of our present essays. As, in the course of our plan, we intend to notice the principal and most striking differences which occur between the skeleton of man and inferior animals, it is requisite that we should glance for a moment over the classes into which the animal kingdom is divided, that we may at once ascertain, and settle in our minds, the broad lines which constitute essential distinctions between those possessing, and those not possessing an internal skeleton, and again between those in whose conformation the skeleton is perfect, or imperfect. The animal kingdom admits of a natural division into two extensive families-those that possess, and those that do not possess an internal articulated skeleton; and each family has its general distinguishing characters. It is a rule, to which we believe there is no exception, that all animals furnished with uncoloured blood are destitute of an internal skeleton, and do not respire through cellular lungs; besides this, they have little in common; we cannot trace in them that regular series, or gradation, which in the other family is so very manifest. Some, incapable either of uttering sound, or moving from the spot where they exist, differ in outward appearance but little from the plant; shapeless and inanimate, and perhaps not conscious of existence; still they fill up their place in the balance of creation. Others again, more exalted in rank, have a distinct head, body, and limbs or extremities, and of these limbs the number is never less than six, but sometimes a hundred or more; some are gifted with wings of delicate network, or covered with feathery down, painted with dies of unequalled richness; some, too, are clad in armour, and furnished with weapons of of fence; still, however, all want an internal skeleton, and their blood is cold and colourless. On the contrary, we may observe, that all animals furnished with red blood possess an internal skeleton, which is articulated, and | | serves as a framework for the muscles and soft parts of the body. All these animals have a definite shape, and though in some the extremities are wanting, yet in all, the head and vertebral column, at least, are perfect. The skull therefore, and vertebral column, we may consider as the essential parts of the skeleton. These animals all possess red blood, but they are further subdivided into those whose blood is red and warm, and those whose blood is red and cold. The first division includes mammalia and birds ; their blood is warm : the second, fishes and reptiles ; their blood is cold, or rather of a temperature but little differing from that of the medium in which they exist. In red and warm blooded animals, the following characters are always found :— the heart consists of two ventricles, and the circulation is therefore double; respiration is carried on by means of cellular lungs, and cannot be impeded or suspended without destroying life; the skeleton is firm and compact, the ribs are never wanting, and seldom the four extremities; the brain fills exactly the cavity of the cranium or skull; the eyes are defended by eyelids ; and the apparatus or organ of hearing, perfect to an exquisite degree, is enclosed in a case of solid bone. But with respect to animals endowed with cold red blood, it is rather by what they want, than by what they possess in | common, that their character is to be traced. The bones of their skeleton are softer and more elastic, from an excess of gelatine in their composition; many are destitute of ribs; many with ribs are unfurnished with limbs; the brain never fills the cavity of the skull; the eyes are seldom protected by moveable eyelids; and the organ of hearing is deficient in delicacy and perfection. Still, however, in all red blooded animals, differing as they do in these circumstances, the skull and the vertebral column are complete. It is true that each class, from man downwards to the lowest, presents minor and characteristic peculiarities, of which the naturalist has availed himself in the arrangement of the animal kingdom in orders, genera, and species. From these preliminaries, which relate to the subject only in a general sense, let us pass on to notice more particularly the nature and structure of the bones, which by their union constitute this beautiful framework, the broad differences of which, as manifest in the general classification of animals, we have imperfectly and rapidly traced. There are few natural objects which the chemist's art has not assayed-nor has any 927 On the Middlesex County Asylum. part of the animal frame escaped his researches; hence we are informed, that the component parts of bone are earthy matter, gelatine, cartilage, and oil. The earthy matter contained in human bones, consists of phosphate and carbonate of lime, with a small proportion of sulphate of lime; in addition to which, in some animals a small quantity of phosphate of magnesia also has been detected. The proportion of earthy matter increases with the age of the bones, while at the same time the proportion of gelatine, of which, in infancy, the osseous structure is almost wholly composed, suffers a proportionate decrease. Thus, in children, the bones, from the predominance of the gelatine, are softer and lighter, but less liable to fracture than in aged persons, in whom, though much harder, they are considerably more brittle. Hence, as has often fallen under our own experience, the bones of the arm in children are frequently bent by accidents, which, had the individuals been aged, would have produced fracture; but the softness and pliability of the bones admitting also of an easy gradual return to the original figure, such accidents are soon recovered. The bones, then, in infancy, as we have just stated, are composed almost entirely of gelatine, and it is on this base that the phosphate and carbonate of lime, which give to them their opacity and consistence, are gradually deposited. But this disposition does not take place in a general diffused and indeterminate manner over the bones; much less are we to imagine that it mingles with the gelatine at once, so as to form an homogeneous mass; on the contrary, we find that nature pursues a method, for the accomplishment of her end, entirely different, and more consonant to the general tendency of her laws. The addition of earthy matter to the yet gelatinous bone, is termed ossification; and this ossification is carried on by a deposition of the lime, in a series of lines, or fibres, at first distinct and separate, but by successive additions gradually coalescing, until the requisite perfection is attained. In the position and arrangement of these fibres on the surface of bones, a certain regularity, according to the figure and use of the specified bone, is always observable; and it may be remarked, that in every instance these lines or fibres originate and proceed from centres, named points of ossification, where, it would seem, the first earthy particles are deposited. In flat or compressed bones, as those of the skull, the fibres proceed from their respective 928 centres in diverging rays; but in the long bones, as those of the arm, they run in parallel lines. The points or centres ossification in the long bones, are generally three; one about the middle, which encircles the bone like a ring, and from which the parallel fibres extend, and a principal one at each extremity, sometimes accompanied with smaller ones. · From these three centres it naturally follows, that three distinct osseous portions are gradually produced, resulting from the progress of ossification extending from each; and the bone is thus originally composed of three separate pieces, which, united by an intervening layer of gelatine, remain long unconsolidated. With respect to the flat bones, especially those of the skull, we must observe, that they have often two or more centres of ossification from which the fibres radiate; but the separate portions thus resulting are not divided, as is the case with the long bones, by a layer of gelatine; for when the extremities of the radiating fibres meet, a junction of a peculiar kind is formed by the serrated edges of each portion becoming locked together; and this is termed a suture, which is sooner or later effaced, a complete union succeeding. Thus the frontal bone, or bone of the forehead, in childhood, is composed of two distinct portions; but as age advances, these become gradually consolidated, and in a few years, even the traces of a suture are lost. It is true, that the skull consists of many bones joined only by sutures, but as these remain uneffaced during life, or are at least seldom only dissipated, the bones thus joined are all accounted as distinct, for it must be observed, that it is only where the sutures are always or usually effaced in childhood, or early life, that a bone originally divided, is accounted as single. Hammersmith. W. MARTIN. (To be continued.) ON THE MIDDLESEX COUNTY ASSYLUM. SINCE writing my last letter for the Imperial Magazine, there has been a meeting of the magistrates of the county of Middlesex, upon the question of granting a hundred thousand pounds for the erection of an asylum for insane paupers. A short delay has been obtained by the party averse to the measure, and I do hope that the scheme will be ultimately given up, and that one more favourable to the purposes of curing mental diseases will be established. Both parties appealed to the feelings of humanity; and so vague are the notions respecting these complaints, that the most opposite |