I suppose that we all consider ourselves to be sufficiently impressed with the importance of ventilation. If I should stop here to declaim against foul exhalations, or to dwell upon the virtues of fresh air, you might feel inclined to interrupt me by saying, "Oh, we know all about that! If you have anything practical to advance, come to the point." Gentlemen, I beg your pardon, but I must say that the great fact concerning ventilation, as yet, is that its strongest advocates are not conscious of one-half the seriousness of the subject; and the second fact is that the supposed means of ventilation prescribed by science fail to secure it.

This, then, is my point to-night - the supreme necessity, still urgent, and universally urgent, for a reformation of the breath of life. I believe in a promised time when the days of a man's life shall again be as the days of a tree. And next to the abolition of vice and sin, I believe that the very grandest factor of such result must be an entire disuse of obstructed air for the lungs. I propose to bring forward some evidence of the necessity, and likewise of the possibility, of a reform so radical and sweeping as this. The subject is too wide for the occasion. I shall be able to read only extracts from what I have prepared, in the few minutes that you can give with patience to my unpracticed lecturing.

The best prescription that doctors have to give (when we are not too far gone to take it) is to live out of doors. Why is this? Why is life out of doors proverbially synonymous with robust health? Why is it that a superior vitality, and a singular exemption from disease, notoriously distinguish dwellers in the open air, by land or sea? Without disparaging the virtues of exercise or of bracing temperature, indispensable as these are for the recuperation of enfeebled constitutions, we must admit that among the native and settled inhabitants of the open air high health is the rule in warm climates as well as in cold, and with the very laziest mortals that bask in the sun, or loaf in the woods. The fact is that simple vegetative health seems to be nearly independent of all other external conditions but that of a pure natural diet for the lungs. Man in nature seems to thrive as spontaneously as plants, by the free grace of air, earth, and sun. On the other hand, the very diseases from which houses are supposed to defend us - that most numerous class resulting from colds - are the special scourge of the lives that are most carefully shielded from their commonly supposed cause - exposure to the open air.

Those diseases diminish, and entirely disappear, just so far as exposure in the pure and freely moving air becomes complete and habitual. Soldiers, inured to camp life, catch cold if they once sleep in a house; and, generally speaking, the inhabitants of the free air contract colds only by exposure to confined exhalations from their own or other bodies, within the walls of houses. The explanation of this is plain and simple: Carbonic acid detained within four walls accumulates in place of the breath of life - oxygen - and narcotizes the excretory function of the skin. The moment that this great and continual vent of waste and impurity from the system is obstructed, internal derangement ensues in every direction. All hands, so to speak, are strained to extra duty to discharge the noxious accumulation. The lungs labor to discharge the load thrown back upon them, with hastened respiration, increased combustion, and feverish heat. The pores of the mucous membrane in the nose, throat, alimentary canal, or bronchial passages, are forced by an aggravated discharge (or catarrh), and this congestive and inflammatory pressure is a fever also.

There is nothing of "cold" about it except as an auxiliary and antecedent, in cases where an external chill has struck upon nerves already half paralyzed by the universal narcotic - carbonic acid - which house dwellers may be said to "smoke" perpetually.

So much for nerve-poison; but blood-poisoning is a still more terrible characteristic of house-protected existence. It is now the almost universal opinion of the medical profession that the whole class of malarial and zymotic diseases that make such frightful progress and havoc in the most civilized communities, are due to living germs with which the exhalations of organic waste and decay are everywhere loaded in inconceivable numbers. They are known to multiply themselves many times over, every two or three hours. They swarm into the blood by millions, through all the absorbents, especially those of the lungs, that drink the atmosphere in which they are suffered to linger and propagate. Mr. Dancer, the eminent microscopist, counted in a sample from such an atmosphere a number of organized germs equivalent to 3,700,000 in the volume of air hourly inhaled by one person. That is over 60,000 germs per minute, and about 2,000 in every breath. In the blood, they still propagate, and feed, and grow, consuming its oxygen, thus defeating its purification, and turning that stream of otherwise healthful and invigorating nutrition into a stream of effete and corrupt matter - a sewer rather than a river of life - or at best an impoverished and impure supply for the support of existence.

The same pestilential but invisible hosts of bacteria, mustered and bred in the close filthiness of Oriental cities, and jungles, swarm out as Asiatic cholera on the wings of the wind, sweeping the wide world with havoc. Settled on the tropical shores of the Eastern Atlantic, they lie in wait for their victims in the sluggish and terrible coast fever. On the western coast of the same ocean, perhaps from some cause connected with oceanic or atmospheric currents, they make devastating irruptions inland, as yellow fever, in every direction where the walls of their enclosure are low enough to be freely passed. These, let us remember, are all essentially the same organic poison that is engendered wherever life and death are plying their perpetual game; and this, like Cleopatra's "worm, will do its kind" in the veins of man, wherever obstructions, natural or artificial, temporary or permanent, interfere with its prompt diffusion in the vastness of the general atmosphere. Our "house of life" stands generously open, for every "inmate bad" to come and go through the absorbent, unquestioned, except in the stomach, where the tangible poisons have to go by the act of swallowing and where they are often challenged and ejected.