jects prepared for easy conquest by previous violations of the laws of health and life. Dr. Mitchell, of Philadelphia, suggests the "cryptogamous origin of epidemic diseases, and some English periodicals have speculated on the alleged discovery of sporules or organic cells, as causes of cholera. But it would seem difficult to ascertain the cause of these causes, even if they are causes, (which is yet to be proved,) without looking to some peculiar antecedent atmospheric condition to account for their production. If this were the proper place it would be easy to show that this classification is more natural, simple, comprehensive, and philosophical, and better adapted to general practical purposes, than the classifications in general use. The extracts we have already given under our XVth recommendation, prove that a similar distinction has been indirectly acknowleged by the best medical writers. Many other similar quotations might be given. We are aware that it may sometimes be difficult exactly to draw the line which separates atmospheric from local causes, though not, as seems to us, for general purposes, in the restricted sense in which we use the terms. It seems to us that any ætiologist would have more difficulty in drawing definite lines to separate contagious from infectious, or predisposing from exciting, or cognizable from non-cognizable causes of disease. XVII. WE RECOMMEND that, in laying out new towns and villages, and in extending those already laid out, ample provision be made for a supply, in purity and abundance, of light, air, and water; for drainage and sewerage, for paving, and for cleanliness. It is a remarkable fact, that nearly the whole increase of the population of Massachusetts, during the last twenty years, is to be found in cities and villages, and not in the rural districts. The tendency of our people seems to be towards social concentration. And it is well to inquire what will probably be the consequences of these central tendencies; and how, if evils are likely to arise from this cause, they may be avoided. It has been ascertained that the inhabitants of densely populated places generally deteriorate in vitality; and that, in the course of years, families frequently become extinct, unless recruited by a union with others from the country, or with other blood of greater vital force. This is a significant fact, which should be generally known. Cities are not necessarily unhealthy, but circumstances are permitted to exist, which make them so. "Every population throws off insensibly an atmosphere of organic matter, excessively rare in country and town, but less rare in dense than in open districts; and this atmosphere hangs over cities like a light cloud, slowly spreading-driven about— falling-dispersed by the winds-washed down by showers. It is matter which has lived, is dead, has left the body, and is undergoing by oxidation decomposition into simpler than organic elements. The exhalations from sewers, churchyards, vaults, slaughter-houses, cesspools, commingle in this atmosphere, as polluted waters enter the Thames; and, notwithstanding the wonderful provisions of nature for the speedy oxydation of organic matter in water and air, accumulate, and the density of the poison (for in the transition of decay it is a poison) is sufficient to impress its destructive action on the living-to receive and impart the processes of zymotic principles-to connect by a subtle, sickly, deadly medium, the people agglomerated in narrow streets and courts, down which no wind blows, and upon which the sun seldom shines. "It is to this cause that the high mortality of towns is to be ascribed; the people live in an atmosphere charged with decomposing matter, of vegetable and animal origin; in the open country it is diluted, scattered by the winds, oxydized in the sun; vegetation incorporates its elements; so that, though it were formed, proportionally to the population, in greater quantities than in towns, it would have comparatively less effect. The means of removing impurities in towns exist partially, and have produced admirable effects; but the most casual observation must convince any one that our streets were built by persons ignorant as well of the nature of the atmosphere, as of the mortality which has been proved to exist, and is referable to causes which, though invisible, are sufficiently evident. "The occupations of men in towns are mostly carried on in-doors, often in crowded workshops, while the agricultural laborer spends the greater part of the daytime in the open air. From the nature of the particles of animal matter thrown into the atmosphere, it is impossible to place the artisan in circumstances as favorable as the laborer; the sun and wind destroy and waft away the. breath as soon as it is formed; but in the workshops of towns the men are shut from the sun, and no streams of the surrounding air carry off the steaming breath and perspiration, so that the mortality of workingmen in the metropolis is much greater than the mortality of women at the corresponding ages." 1 The different sanitary investigations in England have related principally to the subjects suggested in this recommendation ; and facts have been brought to light, in relation to the manner in which many human beings live, that have made a profound impression upon the public mind. "There are," says Dr. Simon, "many, very many courts and alleys hemmed in on all sides by higher houses, having no possibility of any current of air, and (worst of all) sometimes so constructed, back to back, as to forbid the advantage of double windows or back doors, and thus to render the house as perfectly a cul-de-sac out of the court, as the court is a cul-de-sac out of the next thoroughfare. "It is surely superfluous to observe that these localities are utterly incompatible with health. Among the dense population it is rare to see any other appearance than that of squalid sickness and misery; and the children, who are reproduced with the fertility of a rabbit warren, perish in early infancy. In the worst localities probably not more than half the children born survive their fifth year, and of the 3,799 deaths registered last year in the city of London generally, 1,410 were at or under seven years of age. "The diseases of these localities are well marked. Scrofula more or less completely blights all that are born, often extinguishing life prematurely; in childhood, by hydrocephalus; in youth, by pulmonary and renal affections, which you read of as consumption and dropsy, often scarring and maiming where it 1 Fifth Report of the Registrar-General, pp. 418, 419, 420. does not kill, and rendering life miserable by blindness, decrepitude or deformity; often prolonging itself as an hereditary curse in the misbegotten offspring of those who, under such unnatural conditions, attain to maturity and procreation. Typhus prevails there, too, not as an occasional visitor, but as an habitual pestilence. "It is impossible for me, by numbers, to give you an exact knowledge of the fatality of such spots, because, in the greater part of the city, hospitals, dispensaries, and private practice divide the treatment of the sick with the parochial officers, and diminish the returns of sickness which those officers would otherwise have to show. But this I may tell you, as an illustration of what I state, that in the few houses of Seven-Step Alley, there occurred last year 163 parochial cases of fever; in Princes Place and Princes Square, 176 cases; that behind the east side of Bishopsgate, in the small distance from Widegate Street to New Street, there were 126 cases; that behind the west side, from Primrose Street to Half-moon Street, there were 245 cases; that the parish of Cripplegate had 354 cases over and above the number (probably a very large one) treated by private practitioners, by hospitals, and especially by dispensaries. Similarly, though with less perfect information, I am enabled to trace fever to a terrible extent in very many other localities of the city, even on the verge of its better residences, and close behind its wealthiest thoroughfares. "It was in districts such as these that, in 1665, the Great Plague of London found the readiest facilities for its reception; and it was by the destruction of such districts that the Great Fire of the following year rendered the utmost conceivable service to the sanitary progress of the people, and completed their emancipation from the horrors of an unparalleled pestilence. Long intervening years have sufficed to reconstruct these miserable habitations almost after their first type, and to reëxemplify all the evils which belong to them; so completely, indeed, that if the infection of that same plague should light again amongst us, I scarcely know why it might not traverse the city and decimate its population as quickly and as virulently as before. Meanwhile, however, typhus, with its kindred disorders, and the occasional epidemics of influenza, cholera, and other diseases, maintain their attachment to the soil, and require no further reinforcement from the pestilence of other climates." This picture is reproduced, sometimes with more frightful details, in very many places in Europe, and in this country-in Massachusetts! The evils which it portrays may not exist to so great extent with us, as in the ancient cities and populous places of the old world; but even here their magnitude is very much greater than is generally supposed. Places may be found in the cities and towns of this State, as we shall show further on, that are scarcely to be paralleled in England. This fact will be developed to the astonishment of any one who makes the examination. These evils seem almost inseparable from all densely populated places, so long as the people remain uninstructed and not cared for. It is of the highest importance, then, that all proper sanitary measures should be adopted to prevent those calamities which have been suffered elsewhere, and which will inevitably increase with us, unless seasonably prevented. 1. "Light," says the Liverpool Health of Towns Advocate, (p. 125,)" is necessary to health. Dr. Edwards, of Paris, has shown, that if tadpoles be deprived of light, they do not advance beyond that state of development, however well they may be fed, although they increase in size; and he thence concludes, 'that the action of light tends to develop the different parts of the body in that just proportion which characterizes the type of the species:' and that, in warm climates, 'the exposure of the whole surface of the body to light will be very favorable to the regular conformation of the body.' Baron Humboldt strikingly corroborates this opinion, for he says, after a five years' residence amongst many American tribes, 'I have not seen a single individual with a natural deformity.' We may thus conclude that abundance of light is essential to the proper development of form in man: and it follows, as a consequence, that if children, at the time of early growth, be deprived of this necessary agent, their development will be materially modified, and the foundation for a weak constitution will |