LECTURE ON PUBLIC HEALTH. to be as much as fifty grains in a gallon, and I have not found the quantity vary much in several specimens taken from various parts of the city and suburbs. The 30-much admired water at Henwick Hill contains a large portion of solid contents, and the circumstance of its containing a large impregnation of carbonic acid gives it the freshness for which it is admired. The water in Worcester is improved of late years by the deepening of the wells. Until within the last few years most of the wells were only about fifteen feet deep, and the inhabitants were dependent upon the springs in the gravel for the supply of water, which, from the shallowness of the wells, was often mixed with impurities. Since the large drain in the Blockhouse was made, many of the superficial wells have become dry, and this has compelled many persons to sink into the marl for a spring of water. This, although productive of inconvenient expense, to many parties will be found of benefit, by giving a more abundant supply of water. On the whole, then, I can dispel the alarm of those who are afraid of the water of Worcester directly causing disease by its saline impregnations; but a great evil results in an economical point of view. So hard a water is scarcely applicable for washing purposes, and it is also objectionable in tea-making, and for culinary purposes. I think it right, however, to warn you of a danger of another kind, arising from the prevalence of the custom of using lead for vessels holding water, and for pipes conveying it. This custom of using leaden pipes for conveying pump water has been, in some degree, sanctioned by science. It has been asserted with truth that water containing saline matter does not readily dissolve lead; but facts are stubborn things, and so far back as the time of Dr. Wall, that distinguished physician pointed out instances in Worcester where leaden pipes had been corroded by the action of the water. This subject was taken up at the late meeting of the British Association, at Southampton. Mr. Osborne adduced facts to prove that it is desirable to avoid the use of lead in cisterns for receiving water, and also in pipes for conveying it. The result of his experiments seems to show that the presence of chlorine in the water of the New Forest is one cause of that water dissolving the lead. He also discovered other solvent principles. Now, I have reason to believe that the Worcester springs of water not only contain chlorine, but also carbonic acid; and practically I find my suspicions of lead being dissolved by many of the springs of water in Worcester, confirmed by inquiries amongst the plumbers. They tell me that the leaden pipes connected with some of the wells of water remain for years, and are not at all corroded; whilst there are many of the wells of water that are so actively solvents of lead, that they are not unfrequently called upon to repair pipes which are corroded by the action of the water upon them. It is fearful to think that this lead so dissolved is carried by means of spring water into the human system, and becomes the source of insidious and intractable diseases; such diseases often elude 89 the skill of the physician from ignorance of the cause which has produced them. It behoves, therefore, all who value their health to consider this, and if they have leaden pipes or leaden cisterns for their spring water, to ascertain, without delay, whether it is of such a nature as to dissolve the lead. As the over-crowding of the poorer houses in a city is a frequent cause of disease, we should endeavour to improve Worcester in this respect; for although the number of inhabitants to each house is diminished since the commencement of the present century, being now not quite five to each house, and although many new houses have been erected for them, containing better accommodation, and are better situated as to dryness, warmth, and ventilation, yet those inhabitants who live in the old parts of the town, which were formerly the seat of the woollen manufactories, are not well provided with means of removing the filth which accumulates in them. The lodging houses especially are very dirty, and the average number of inhabitants is excessive, and the means of ventilation are very deficient; so that the effluvia and other causes here operate with intensity, so as in seasons of predisposition to this class of affections to be productive of contagious diseases. The mode in which the streets are laid out-their width or compactness their pavement-their drainage--their exposure to the sun and to the wind, are considerations of much importance. The difference of a few paces may make a very considerable difference to the health of the inhabitants; thus at Rome, certain streets, nay, certain parts, sides, and even houses of some streets, are more damp, chilly, and exposed to the malaria than others. Certain parts of our own city have, until lately, been remarkable for fever; the Blockhouse-fields especially so, until the large drain was constructed. There are again other parts of Worcester where the dwellings are very old, and masses of building are accumulated together, which prevents ventilation and the access of the solar influence. There is no doubt that the inhabitants of these parts would be more healthy, if many of the old walls and masses of houses were pulled down, and thus open spaces occasioned where the air may circulate more freely, and as it were, percolate these districts. I have no improvement, except as to drainage, to suggest in our principal streets; they are wide and well ventilated, and whenever a gust of wind comes it thoroughly perflates them, and removes impure exhalations. These exhalations, I am sorry to say, often arise; for the drainage, even in our principal streets, is yet very imperfect. The sewers, if they can be so called, are superficial, and are not constructed on any general and comprehensive plan. All this must be remedied before Worcester can derive, in point of health, all the benefit for which its natural situation appears to have destined it. Mr. Austin, in his report to the City Commissioners, has submitted to the city a proposition for a most effectual system of sewerage, by which most of the evils arising from deficient drainage we have so long had reason to complain of, may be removed. Great indeed, therefore, will be the disappointment, if the faithful city should not arouse itself, put forth all its energies, and carry out this necessary hygienic improvement. There are several other points to which, if there were time, I should allude more fully, but to which I shall now only cursorily direct your notice. It is placed beyond all contradiction that the state of the graveyards within our cities is a frequent source of disease, and Worcester is open to this evil. The difficulties that have opposed themselves to better sanatory arrangements in this respect are great; but let us hope that cemeteries without our cities may gradually become the approved mode of sepulture by all classes of the inhabitants, and we shall then reap the reward in improved public health. The slaughtering of animals is another evil which calls for a remedy, as does also the keeping of animals, as horses, pigs, dogs, &c., which a better system of police would render less noxious to the inhabitants. The clothing and diet of the humbler classes are of much importance. Worcester is not subject to those great vicissitudes to which large manufacturing towns are liable, and consequently the labouring population are not so much affected by them, their prosperity never being very great nor their adversity so appalling. A corresponding condition of their food and clothing is the result. Vegetable food and tea are in great request, and the failure of the potato crop has been a source of difficulty. I shall not, however, here dilate upon this, but I may remark, that the causes producing disease in the vegetable kingdom, seem also coincidently to have affected the animal. Epizootics amongst horses and cattle have been observed in visitations will come, and that they fall most heavily where the laws of public health are most neglected. This, then, is our encouragement. Providence puts within our power certain means of prevention. We | know them. They are plain before our eyes. Shall we, then, be indifferent to these things? Is our life so long that we can afford to lose a considerable portion of it by neglect? The future must answer these questions. Hitherto indifference to these matters has been abundantly evident amongst all classes. I feel that I have occupied more time than the nature of these meetings will well allow, but you will excuse me if I have delayed you too long, when you consider that the subject on which I have been addressing you is one in which, as Christians, and as men, we are all deeply interested; for however great may be the honours of those who by brilliant exploits add to the glory of their country, few will deny, that those deserve well, and contribute to her political welfare, who add to the health and happiness of the poor, who are always the mass of the community. Depend upon it, whatever tends to exalt them in the scale of moral and rational creatures, tends also in the same degree, to exalt the nation, of which they must always form the largest part in political power. None but those who are in the habit of mingling with the lower classes can have a notion of the intimate connection which exists between physical and moral degradation. From religious motives alone then we may insist upon the necessity of endeavouring to improve the condition of the poor, and we should never weary in our efforts to induce the Legislature to devote their energies to this matter. many places, and the reports of the Registrar THE LAW OF THe morpholoGY OR META General for 1846 shews an increase in the mortality, so that in fact, whilst we are planning and considering what can be done to diminish the insalubrity of towns, Providence sends a visitation which tells us that all our endeavours without his concurrence are vain. For some years past there was reason to believe that the causes of mortality in towns were less operative. The Registrar General in his report for 1845, says, in the last three years the price of provisions was cheaper, the commerce and manufactures of the country were more active, the relief to the destitute more liberally administered, and the wages of artisans higher; and all these circumstances favourable to public health undoubtedly contributed to the reduction of the mortality observed. In the midst, however, of all these pleasing prospects, in 1845 and 1846 there is a visitation of a blight in the potatoes and other vegetable productions,—and what is the result? Why in 1846 epidemic disease to a considerable extent prevails in the three kingdoms; the mortality has increased, and in many parts has been one fourth, and one third, and in some instances double the amount of former years. Worcester has been leniently visited, and the epidemic affection has been lighter than in many parts, qut still enough has occurred to show that epidemic MORPHOSIS OF THE TEXTURES OF THE HUMAN BODY. (Fourth Series of Experimental Researches.) By WILLIAM ADDISON, M.D., F.R.S., Malvern. (Continued from page 62.) III. EMBRYO AND ADULT TEXTURES. The microscopical researches of Dr. MARTIN BARRY and others have established the fact, that the first texture of the human embryo and its appendages is corpuscular, or incoherent cellular, that is to say, a texture composed of cells or corpuscles, which have exceedingly thin walls, are very soft and brittle, having but a slight coherency. These cells have many analogies with the cells of the cellular textures of vegetables,-with the protoplasma cells of MOHL, in preceding all the solid formations, and containing a viscous colourless mass, mixed with granules or molecules, and with the incoherent chlorophylle cells of a leaf, in containing a material essential to the growth of the future and more important parts of the structure, in both cases, the material being a secreted or elaborated one. When the embryo is growing, the transparent membrane or amnion formed around it is first MORPHOLOGY OF THE TEXTURES. | 91 corpuscular, then coherent cellular, and then fibrous; During infancy and youth all the later-formed texand the walls of the blood-vessels ramifying upon it, tures are undergoing different phases of metamorundergo the same changes; they are first corpuscular, phosis, until the adult period or permanent form is then cellular, and lastly fibrous. This then is the established. At the adult period the permanent texorder of the morphology, in respect of the membranous tural form of the grey portion of the brain, of the envelopes of the embryo,―viz., first corpuscular, then liver, the intestinal villa, and the plexus choroides, &c., -cellular, and then fibrous. In the embryo itself, a is corpuscular,-a soft, brittle, tender, and incoherent month or five weeks old, and half an inch in length, cellular texture. The parenchyma of the lungs is several textural groups, representing the head, eyes, coherent cellular. The areolar textures, the dura and extremities, the spinal column, liver, and heart, mater, pia mater, pericardium, &c., fibrous; and, may be discriminated. All these groups, when ex- without making special reference to nerve-tubes, and amined with the microscope (700 linear,) are found muscular fibrillæ, there are also fibro-cartilaginous, to consist wholly of incoherent cells or corpuscles, cartilaginous, and osseous textures.* But, as all these soft and easily separable from each other; and they textures were at first soft, brittle, incoherent, and corare all filled with a protoplasma, a viscous colourless puscular, the permanent form of some textures; then matter, mixed with molecules. At this early period, | coherent-cellular, the permanent form of other texnothing resembling a coherent cellular texture can be tures; then fibrous, fibro-cellular, and cartilaginous, found; all is soft, pulpy, and brittle; there are neither the permanent forms of others; and then osseous; so blood-vessels nor fibres, nor can anything hard or therefore it is concluded, that the law of the metamorcoherent, resembling cartilage or bone, be detected.phosis in the human structure is from soft, semi-fluid, When the embryo is four months old and seven inches incoherent, corpuscular textures, to the coherent cellong, the brain, liver, &c., are groups of corpuscular lular; from these to fibrous, fibro-cellular, and cartilatexture,—soft, brittle, and incoherent. In the lungs, ginous; and lastly to bone. nothing resembling the adult pleura can be dissected, even with the utmost care, from their surface; and the thinnest section that can be made, gives (with a microscopic power of 700,) a coherent cellular texture, mingled with the isolated cells of an incoherent texture. The skin, both epidermis and cutis, viewed with a power of eighty diameters, exhibits a great number of small dots or granulations, and so likewise does the pericardium and the other (will-be) fibrous membranes. These granulations, when more highly magnified (700,) are found to be groups of coherent cellular texture, and the whole texture exhibits the same character. The young hair upon the head is very clearly a coherent cellular texture; the heart is a mass of elongated coherent cells; and it is only in the pericardium and other analogous strong membranes that waved fibres have yet appeared. The muscular fibrillæ are more advanced, and have their transverse markings; but nothing resembling nerve fibres (properly so called,) can be detected, though cells with long projecting tubes, filled with a molecular matter, may be seen mingled with others, especially in the embryo texture of the spinal cord. In the bones of the cranium, the nascent osseous cylinders exhibit small, bony, or hard, cell-like particles, dispersed in a semi-transparent matrix, surrounded and enveloped on all sides in a very vascular fibro-cellular texture. I am not aware that there is any difference of opinion among physiologists as to the general order in which the textures of the human structure appear, and I presume they are ready to admit that soft and but slightly-coherent cellular or corpuscular groups, precede the coherent cellular textures; that the cellular precede the fibrous and cartilaginous, and the cartilaginous precede bone. They are at least agreed upon the analogous fact in vegetable structure, “cells containing a viscous colourless mass mixed with granules everywhere," as MOHL observes "preceding the first solid formations." In the human embryo then, the primary metamorphoses, out of which the future textures arise, take place in groups of corpuscular texture, before any circulating blood, or any blood-vessels can be detected; and the singular variety of the metamorphoses, even in a single organ, may be judged of from the structures of the eye. At this early period, it is by investigations with the microscope in the midst of these corpuscular groups, that the primary changes must be sought; but when blood-vessels or rather blood-channels are visible, and there is blood, a cellular or corpuscular fluid circulating through them, it is then along the inner margins of their walls that the nature of the subsequent metamorphoses, those which establish the form and quality of the adult organs,-must be looked for. The growth of the textures of the human embryo prior to the circulation of a current of blood-cells, is In the fœtus at birth, the soft corpuscular textures have assumed nearly their permanent characteristics; but this is far from being the case either with the fibrous, cartilaginous, or osseous textures, corpuscles or cells being still the most abundant elements in the fibrous textures, and largely mingled with the youngtures, but there are many of a mixed character; the pleura fibres of the walls of the blood-vessels. These are the broad distinguishing types of the tex is fibro-cellular, and the mucous texture of the air tubes is fibro-corpuscular. in every respect analogous to the growth of the vege- | to puberty, are gradually ascending to their permanent table embryo prior to the formation of a green leafy parenchyma. And, as in the human structure, the blood current is essential to continued growth and future textures, so likewise in the vegetable structure, in the leafy parenchyma, and moreover, as vegetable structures are disposed to revert to a leafy parenchymaa, so an analogous disposition will be shown to exist in animal textures. forms, some reaching it soon, others later, so therefore the elements of the walls of the blood-vessels, and particularly those of the nutrient vessels, vary not only in the different organs, but in the same organ, pari passu, with the morphological evolution,-that is to say, in other words, they vary with the age of the organism, differing in the same place in the infant from the embryo; in the child from the infant; and in the adult from the child. V. STRUCTURE OF THE LUNGS. The air-cells of the lungs are not indiscriminately thrown together in the interior of the organ; on the contrary, they are symmetrical with the branches of the air-tube, and collected or associated in numerous small communities or groups, each group forming what is termed a lobule; many lobules grouped together form a lobe, and five lobes form the two organs called the lungs. A pulmonary lobule is a perfect respiratory organ in itself, the whole lung being but a series of reduplications of the same structure-an aggregate of lobules. At one of the corners or angles of a lobule, a division of the air-tube, and an arterial blood-vessel enter into its interior, and at the same place a vein comes out, and by these three cylindrical structures the lobule is connected with its fellows. The mem IV. STRUCTURE OF BLOOD-VESSELS. The anatomical or structural elements of the adult blood-vessels, as long as their course lies embedded in a fibro-cellular or areolar texture, and whilst merely transmitting the current of the blood, although varying a little in different places, still uniformly consist of sundry layers of fibrous and fibro-cellular textures, the fibres in some of the layers being enlarged longitudinally, parallel with the course of the vessel, others circularly, passing around the vessel. The fibres are thick and strong, especially the outer layers, in proportion to the size of the vessel, or of the column of blood it conveys; and they inclose in their interstices, and are firmly united with, the nuclei of cells, and with a vast amount of granular and molecular matter, sometimes mingled with globules of oil or fat. In the very small branches of the blood-vessels, those which are on the point of leaving the fibro-cellular texture inter-brane which forms the walls of the air-cells, constitutes posed between the lobular subdivisions of the various organs, and which are therefore approaching the scene of the nutritive function, the vascular walls or coats of the vessels are less fibrous; and it is evident from a 'careful examination, that they more and more partake of forms that are identical with those which constitute the parenchyma or special texture they supply; until at length in the true nutrient or capillary channels it appears to be impossible to discriminate (certainly it is impossible to observe any practical distinction,) between the elements of the parenchyma and the walls of the vessels. Two textures easily examined, may be instanced in illustration:-In the pia mater the walls of the vessels are fibrous,-a transparent fibrous parenchyma or membrane; in the plexus choroides they are corpuscular, a corpuscular parenchyma. But, as all the various textures, from the beginning in the embryo up to the period of birth, and from birth The increasing importance of the elements of the walls of blood-vessels, as the vessels diminish in size, is indicated by the fact, which may be demonstrated in the vessels of a transparent texture, that the thickness of the wall is, as a general rule, inversely proportional to the diameter of the column of blood it conveys. In a large vessel, 1-100th of an inch, the thickness of the coat visible on each side as viewed through the microscope (703, is not more than one third or one fourth the diameter of the column of blood; whereas in a small vessel 1-500th or 1-1000th of an inch, the reverse proportions are frequently seen; the thickness of the wall of the vessel being three or four times greater than the diameter of the blood-stream. Hence there is no difficulty in clearly seeing the stages of nutrition hereafter pointed out. the parenchyma or proper texture of the lungs, and the capillary vessels so densely distributed upon it have no other coats or boundaries than those furnished by this parenchymatous texture. The practical point to be insisted on, with a view to the correct understanding of the pathology and diseases of the lung, is that involving the relation of the walls of the air-cells to the extremities of the air-tube on the one hand, and to the blood-vessels on the other. The air-tubes and blood-vessels before entering into the interior of the lobules, run in the spaces between them, and here, cushioned as it were upon an areolar texture, they have severally their own distinctive elements and structures; but within the lobules, after sundry subdivisions, they all terminate in, and their textures become continuous with, the walls of the air. cells,-that is to say, with the parenchymatous texture; and here it is impossible, even with the microscope, to discriminate between the elements continuous with, or prolonged from, the coats of the blood-vessels and those continuous with, or prolonged from, the air-tubes, —that is to say, in other words, the outer surface of the thin transparent wall of every air-cell is in close relation with the interior of the blood-vessels, and its inner surface is as closely related to the air-tubes. The parenchyma of the lung is usually described by anatomical writers as a mucous texture,—that is, a secreting texture, but it has none of the anatomical characters of a mucous texture, its perfect transparency and elasticity resemble much more the characters of a MORPHOLOGY OF THE TEXTURES. 93 fibrous or serous texture; moreover, it is well-known in their disposition. The dura mater and pia mater that its capillaries have a special function, and no are both fibrous membranes, surrounding, supporting, analogy whatever exists between them and the capil- and protecting in bulk, the whole brain or central laries of a secreting texture. In the adult lung the organ of the nervous system. The dura mater, as its parenchyma is coherent cellular; the areolar texture name I suppose implies, is an exceedingly strong and interposed betwen the lobules is fibrous and fibro-cel- coherent texture, transmitting immense columns or lular; the pleura which covers the whole lung, and streams of blood to and from the brain, yet is itself lines the interior of the cavity of the chest, is both scantily supplied with nutrient capillaries. But the cellular and fibrous,-cellular on its smooth free sur-arterial currents traversing the dura mater, and those face, and fibrous beneath. The mucous texture of the interior of the air-tube is fibro-corpuscular,—that is, composed of fibres intermingled with incoherent cells, and the blood is a corpuscular fluid, flowing in streams over the walls of the coherent cellular parenchyma. But in the embryo all pulmonary textures are composed of soft, and but slightly cohering cells; in the fœtus they are partly corpuscular, and partly coherent-cellular; and during infancy and youth the walls of all the nutrient vessels, even of those which have become fibrous, are largely charged with incoherent corpuscles or cells. Hence then, the morphology of the textures of the lung is corpuscular, cellular, and fibrous; and there is nothing, except in the larger branches of the air-tube, of a cartilaginous or osseous texture. VI. PHYSIOLOGICAL ANALYSIS OF THE CORPUSCULAR, CELLULAR, AND FIBROUS TEXTURES. Keeping in view the distinctions insisted on between the corpuscular and the cellular textures, it is evident that the corpuscular are the secreting textures, and the cellular non-secreting ones, that is to say, the cells or corpuscles of the secreting textures, with their thin walls and elaborated contents, are temporary and evanescent elements; while the cells of the coherentcellular textures, with their strong elastic and transparent walls, are comparatively durable and permanent; and as the rapidity of the changes and displacements which the elements of a structure undergo, is in a direct ratio with their importance in the functions of nutrition, secretion, and life, so therefore the cells or corpuscles of the corpuscular textures are more active or energetic than the cells of the cellular. still larger ones arising from other quarters, before they can be admitted into the soft corpuscular texture of the brain, must be divided and subdivided many times into the smallest possible streams, and the force of the heart's action subdued by sinuous turns and windings. For these ministerial purposes the much more fine and delicate fibrous texture of the pia mater is interposed, which not only affords space and area for the subdivisions of the blood-current, thereby becoming extremely vascular, but slipping down between all the lobular subdivisions of the organ, (here termed convolutions,) it enters into the recesses, supporting and limiting and conveying vessels, through which the blood reaches and returns from all parts of the soft and tender parenchyma of the great organ of life and being. Lastly, the cellular parenchyma of the lung is not tender, opaque, and brittle, like the corpuscular parenchyma of the liver, but is on the contrary exceedingly coherent, elastic, and transparent, and these anatomical characters indicating, as before observed, that the parenchyma of the lung is not a place of active nutrition or cell-elaboration,-not a secreting texture; and although eminently vascular, more so, perhaps, than any other texture of the body, still the vascularity is analogous to that of the pia mater, a ministerial and not a nutritive vascularity, the analogies of the texture being altogether with the fibrous non-secreting, and not with the corpuscular and secreting textures. This corresponds with facts; the only outlet and inlet to the lungs is by the windpipe; and if the air-cells, which have been computed to number 1.744.000.000 in each lung, or if an expanse of membrane equal in area to 1500 square feet, were a secreting membrane in the ordinary and proper acceptation of the term, persons would be always swallowing, or spitting, or coughing, which we know cellular texture of the pulmonary parenchyma allows the finer and vapourous elements of the blood to transude its walls, but it does not, I conceive, in the proper sense of the word, give rise to a secretion. Again contrasting the corpuscular with the fibrous textures, the latter perform the comparatively mechanical offices of separating, investing, and limiting in bulk, the different groups of the various corpuscular and cellular textures, engaged in the more active func-in health is not the case. The fine transpararent tions of life, transmitting the larger columns of blood to and from them. These functional distinctions are indicated by the anatomical fibrous element, and by the species of vascularity observable in the texture. The corpuscular or secreting textures are everywhere traversed by multitudes of nutrient vessels, specially disposed in different organs; whereas the fibrous nonsecreting ones, although in some instances extremely vascular, in consequence of having to transmit a multitude of small vessels, have yet comparatively few nutrient capillaries, and these variable and irregular (To be continued.) |