The purest and the freshest air, then, which Nature has provided for her breathing creatures, is at best largely impregnated, with elements inimical to the life and health of sentient beings. Every inhalation is accompanied with a multitude of things animate and inanimate, crude and impalpable, active and inert, which enter the lungs and through them find free, unobstructed access to the circulation, and through this, to the heart and brain, inciting a warfare of disease and conservation in that medium, which can only end with their elimination or the final decadence of the animal powers. Surely no housewife finds greater difficulty in keeping her house pure and sweet than does Nature in guarding the life-blood from the intrusion of dirt, fungi, and other foreign elements, and ridding it of them when once they have invaded that life-giving fluid. If all mankind knew how impure is the purest air, and how inexpressibly vile is foul air, the number who now "croak" for pure air and free ventilation-for open windows and exposed fire-places—would be largely increased; and the community would enjoy, in consequence, greater immunity from those disorders which now put the majority of mankind into little. coffins and narrow graves.

What countless morbific agencies therefore impregnate the atmosphere, unseen by the naked eye, and unappreciated by the unaided sense! Many of them are too diminutive for the microscope, or even to be estimated by the mathematical powers of the human mind; a world of infinity within the finite, which man can never fully explore, but of whose existence he is compelled to infer. The logic of the known, here, as elsewhere, inevitably impels him to advance to the unknown and to the unknowable!

Having thus but barely entered this part of our subject, we pass to the consideration of a few of the most prominent and noticeable effects of morbific air upon the functions of human life.

We think it may be safely affirmed that every endemic fever owes its existence mainly to impurities in the air in which the victims live or try to live. If one examine those

admirable sanitary maps which usually accompany the annual health reports of New York, Boston, London, and other cities, he will find ample confirmation of this assertion.

Where there are a dense population and crowded tenants, there lurk the horrid skeletons of pestilence and death. Some mistaken poet hath said that "death loves a shining mark!" The observation of the physician does not support the imagination of the poet. The records of the health department show conclusively that death prefers dark spots, shaded marks; his choicest victims being those unwashed creatures who inhabit unlighted and foul-air abodes. It is curious to observe that, when cholera "arrives" in New York, he invariably seeks out for his first victim some poor, wretched starvling, the miserable occupant of some filthy tenement-house in the foulest part of the city! And when yellow fever comes," instead of putting up in first-class quarters, he selects the worst, in which to begin the harvest of death.

Such abodes are always, the head-quarters of all the distinguished pestilential guests, as well as of those of the obscurer sort, and the centre from which their attacks upon more wholesome districts are made. Hence we see in this fact how vitally the improvement of the surroundings of the lower classes concerns the interests of the higher, or more well-to-do.

Small-pox is, likewise, a habitat of foul-air abodes. Foul air generates it in the beginning, and foul air propagates it in the end. The districts where it prevails are always those of the worst and dirtiest in the city. The worst phases of the disease are to be found there, and only by exception anywhere else. Every physician will tell us that second basement cases are the most malignant and the most numerous of any with which he has to deal. Its fatality is almost wholly confined to those who live in filth and breathe morbific air.

With no desire to discourage vaccination when judiciously performed, still we must affirm that a pure, sweet home is a more effective prophylaxis of the disease. If the poor had

this they could safely dispense with the barbaric expedient of vaccination. Indeed, we are not sure but that the vaccination fee spent for soap and whitewash would be a more profitable investment, even as things now are. Vaccination is one of those abominable time-serving expedients which practicalminded geniuses sometimes succeed in fastening upon the medical profession and the common mind. The medical profession is literally loaded down with them to-day; and it would redound to its glory and to the lasting advantage of mankind if it would imitate the wisdom of the theological profession, and throw some of them overboard. On this point, however, opinions differ.

Measles, scarlet fever, and typhus, are foul-air products. They could not be bred in sweet homes and pure environments. They are all both a cause and a sequence of impure air. Being at first propagated by filth, they in turn poison the air with their own infection, and spread their peculiar seedgerms of disease far and wide, to take root and develop characteristic effects whenever a favorable nidus is found to receive. them.

Diphtheria is likewise a disease of foul-air origin. Whether it occur endemically in thickly-settled and over-populated districts; or in the miserable tenements of the poorer classes; or in low, filthy localities near the terminus of sewers, or the dumping-ground of city offal; or from leaky drains and untrapped waste-pipes; or from the noxious ebullitions of stationary wash-basins, wash-tubs, sinks, and in-door water-closets; or the noisome exhalations of confined rubbish in sub-cellars, the cause is one and the same, namely, foul air. Whenever the malady occurs in salubrious localities the cause is to be sought within the confines of the household, and suggests the propriety of putting that "sacred" domain of the individual in wholesome order.

In this general summary of the morbific effects of impure air, we must not overlook scrofula and consumption. Bando. logue, an eminent French physician, affirms, "that the repeated respiration of the same atmosphere is a primary and efficient

cause of scrofula,' and that, if there be entirely pure air, there may be bad food, bad clothing, and want of personal cleanliness, but that scrofulous diseases cannot exist." Again, he says: Invariably, it will be found on examination that a truly scrofulous disease is caused by a vitiated air; and it is not always necessary that there should have been a prolonged stay in such an atmosphere. Often a few hours each day is sufficient; and it is thus that persons may live in the most. healthy country, pass the greater part of the day in the open air, and yet become scrofulous, because of sleeping in a confined place where the air has not been renewed.'"* Dr. Bandologue's observations have been confirmed by many credible writers, among others the eminent physicist, the late Dr. Neil Arnott, of England. Dr. Black, in The London Lancet, argues that impure air is more prolific of cardiac disease than is any other cause. "In thousands of instances of cardiac disease life is thus sacrificed, when, if the proper ventilation of the bedrooms had been observed, the subjects of such disease might, despite the cardiac mischief, have continued to live for an indefinite time." But what is true of cardiac disease is equally true of phthisis and every other form of scrofulous disease.

No part of the animal economy is, in fact, so likely to be compromised by poisons in the air as the lungs. The health, strength, and integrity of those delicate organs are directly dependent upon pure solarized air. The condition of the lungs and the quality of the air is so intimate, the reciprocity is so complete, that a popular medical writer maintains that atmospheric air is the natural food of the lungs. While one may justly question the soundness of that hypothesis, he cannot doubt the intimate sympathy which exists between them and the air, and for reasons quite obvious to any one: the noxious properties of the air producing irritation and disease of the sensitive mucous membrane which lines the air-cells and tubes of those organs, besides corrupting the fountain whence comes all growth and

* Cited by Huxley and Youmans. -Physiology and Hygiene, p. 288.

nutrition-the blood. These effects are manifest in the densely inhabited portions of large cities. They are found in the habitations of the poor, indigent, and ignorant everywhere. One cannot mistake them. These victims of foul air have an earthy, haggard complexion; the breath is offensive; nutrition defective; the lips have lost the vermilion tint; the cheeks are collapsed and the cheek-bones elevated; the form is wasted; the chest is sunken, and the shoulders stooping. There is a dry, hollow cough and shortness of breath which suggest dismal forebodings of that grim horror, death!

According to Dr. MacCormac, "induced consumption has its origin in rebreathing expired air. Persons of a delicate constitution, or organization, should," he says, "sleep alone, and, if possible, in spacious rooms, thus insuring a larger supply of pure, uncontaminated air; and the window-sash should also invariably be slightly raised on retiring. When the dormitory is small, if not carefully ventilated, oxygen, the essential element that supports life, is quickly exhausted, and the individual takes back into the lungs carbonic-acid gas, which is so destructive of life-the whole system becoming deranged, the air-cells ulcerating, and, with the destruction of these, the whole bronchial region falling into disease."

Then there are scorbutic affections. The depravity of the blood shows itself in disease of the skin-pustules, abscesses, suppurations, tumors, enlarged glands, fungoid growths, exortoses, excrescences, cams, etc. The flesh of such people is unhealthy; slight wounds run into unhealthy suppuration, and are difficult to heal. Their blood is inflammable, and kindles rapidly into malignant fever upon the slightest incitement or provocation.

Moreover, upon the mind, the morbific effects of foul air are, if possible, still more pronounced. Indeed, the mind is the first to suffer from unwholesome surroundings, as it is more sensitive to impressions of every kind than is the lower physical powers. These depressing effects are likewise more manifest in proportion to the cerebral development. The student, or one who uses his higher mental faculties largely,