How Disease Germs Grow.—Experiments having shown that no life is known to spring from inanimate matter, we may reasonably suppose that just as wheat does not grow except from seed, so no disease occurs without some disease germ to produce it. Then, again, we may logically assume that each disease is due to the development of a particular kind of germ. If we plant smallpox germs, we do not reap a crop of scarlatina or measles; but, just as wheat springs from wheat, each disease has its own distinctive germs. Each comes from a parent stock, and has existed somewhere previously….Under ordinary circumstances, these germs, though nearly always present, are comparatively few in number, and in an extremely dry and indurated state. Hence, they may frequently enter our bodies without meeting with the conditions essential to their growth; for experiments have shown that it is very difficult to moisten them, and till they are moistened, they do not begin to develop. In a healthy system they remain inactive. But anything tending to weaken or impair the bodily organs, furnishes favorable conditions, and thus epidemics almost always originate and are most fatal in those quarters of our great cities where dirt, squalor, and foul air render sound health almost an impossibility…. Having once got a beginning, epidemics rapidly spread. The germs are then sent into the air in great numbers, and in a moist state; and the probabilities of their entering, and of their establishing themselves even in healthy bodies, are vastly increased….Climate and the weather have also much influence on the vitality of these germs. Cold is a preventive against some diseases, heat against others. Tyndall found that sunlight greatly retarded and sometimes entirely prevented putrefaction; while dirt is always favorable to the growth and development of germs. Sunshine and cleanliness are undoubtedly the best and cheapest preventives against disease.—"Disease Germs" Chambers's Journal.

You know the exquisitely truthful figures employed in the New Testament regarding leaven. A particle hid in three measures of meal leavens it all. A little leaven leaveneth the whole lump. In a similar manner a particle of contagium spreads through the human body, and may be so multiplied as to strike down whole populations. Consider the effect produced upon the system by a microscopic quantity of the virus of smallpox. That virus is to all intents and purposes a seed. It is sown as leaven is sown, it grows and multiplies as leaven grows and multiplies, and it always reproduces itself….Contagia are living things, which demand certain elements of life, just as inexorably as trees, or wheat, or barley; and it is not difficult to see that a crop of a given parasite may so far use up a constituent existing in small quantities in the body, but essential in the growth of the parasite, as to render the body unfit for the production of a second crop. The soil is exhausted; and until the lost constituent is restored, the body is protected from any further attack from the same disorder. To exhaust a soil, however, a parasite less vigorous and destructive than the really virulent one may suffice; and if, after having, by means of a feebler organism, exhausted the soil without fatal result, the most highly virulent parasite be introduced into the system, it will prove powerless. This, in the language of the germ theory, is the whole secret of vaccination.—TYNDALL.

Disease Germs Contained in Atmospheric Dust.—Take the extracted juice of beef or mutton, so prepared as to be perfectly transparent, and entirely free from the living germs of bacteria. Into the clear liquid let fall the tiniest drop of an infusion charged with the bacteria of putrefaction. Twenty-four hours subsequently, the clear extract will be found muddy throughout, the turbidity being due to swarms of bacteria generated by the drop with which the infusion was inoculated. At the same time the infusion will have passed from a state of sweetness to a state of putridity. Let a drop similar to that which has produced this effect fall into an open wound: the juices of the living body nourish the bacteria as the beef or mutton juice nourished them, and you have putrefaction produced within the system. The air, as I have said, is laden with floating matter which, when it falls upon the wound, acts substantially like the drop….A few years ago I was bathing in an Alpine stream, and, returning to my clothes from the cascade which had been my shower bath, I slipped upon a block of granite, the sharp crystals of which stamped themselves into my naked shin. The wound was an awkward one, but, being in vigorous health at the time, I hoped for a speedy recovery. Dipping a clean pocket handkerchief into the stream, I wrapped it round the wound, limped home, and remained for four or five days quietly in bed. There was no pain, and at the end of this time I thought myself quite fit to quit my room. The wound, when uncovered, was found perfectly clean, uninflamed, and entirely free from pus. Placing over it a bit of gold beater's skin, I walked about all day. Toward evening, itching and heat were felt; a large accumulation of pus followed, and I was forced to go to bed again. The water bandage was restored, but it was powerless to check the action now set up; arnica was applied, but it made matters worse. The inflammation increased alarmingly, until finally I was ignobly carried on men's shoulders down the mountain, and transported to Geneva, where, thanks to the kindness of friends, I was immediately placed in the best medical hands. On the morning after my arrival in Geneva, Dr. Gautier discovered an abscess in my instep, at a distance of five inches from the wound. The two were connected by a channel, or sinus, as it is technically called, through which he was able to empty the abscess without the application of the lance.

By what agency was that channel formed—what was it that thus tore asunder the sound tissue of my instep, and kept me for six weeks a prisoner in bed? In the very room where the water dressing had been removed from my wound and the gold beater's skin applied to it, I opened this year a number of tubes, containing perfectly clear and sweet infusions of fish, flesh, and vegetable. These hermetically sealed infusions had been exposed for weeks, both to the sun of the Alps and to the warmth of a kitchen, without showing the slightest turbidity or signs of life. But two days after they were opened, the greater number of them swarmed with the bacteria of putrefaction, the germs of which had been contracted from the dust-laden air of the room. And, had the pus from my abscess been examined, my memory of its appearance leads me to infer that it would have been found equally swarming with these bacteria—that it was their germs which got into my incautiously opened wound. They were the subtile workers that burrowed down my shin, dug the abscess in my instep, and produced effects which might well have proved fatal to me.—TYNDALL.

Disease Germs Carried in Soiled Clothing (p. 89).—The conveyance of cholera germs by bodies of men moving along the lines of human communication, without necessarily affecting the individuals who transport them, is now easy to understand; for it is well established that clothes or linen soiled by cholera patients may not only impart the germs with which they are contaminated to those who handle them when fresh, but that, after having been dried and packed, they may infect persons at any distance who incautiously unfold them. Thus, while the nurses of cholera patients may, with proper precautions, enjoy an absolute immunity from attack, the disease germs may be introduced into new localities without any ostensible indication of their presence. It is obvious that the only security against such introduction consists in the destruction or thorough disinfection of every scrap of clothing or linen which has been about the person of a cholera patient.—DR. CARPENTER.

I have known scarlet fever to be carried by the clothing of a nurse into a healthy family, and communicate the disease to every member of the family. I have known cholera to be communicated by the clothes of the affected person to the women engaged in washing the clothes. I have known smallpox conveyed by clothes that had been made in a room where the tailor had by his side sufferers from the terrible malady. I have seen the new cloth, out of which was to come the riding habit for some innocent child to rejoice in as she first wore it, undergo the preliminary duty of forming part of the bed clothing of another child stricken down with fever. Lastly, I have known scarlet fever, smallpox, typhus, and cholera, communicated by clothing contaminated in the laundry.—DR. RICHARDSON.

THE SANITARY HOME (see p. 94).—1. The Site.—First and foremost of all the things you are to consider, is the healthfulness of a situation. The brightest house and cheeriest outlook in nature will be made somber by the constant presence of a doctor, and the wandering around of an unseen, but ever felt, specter in the shape of miasm….Malaria-malus, bad; aria, air—means, in its common definition, simply bad air. Miasma is its synonym,—infecting effluvia floating in the air. Because, as everybody knows, certain places have always chills and fever associated with them, and other places have not, it follows that between such places there is some fact of difference; this fact is the presence of miasm, a cause of disease, having a signification associative with the locality….

Vegetation, heat, and moisture: these are the three active agents in the production of miasma, to which a fourth is to be added, in the influence of non-drainage, either by the way of the atmosphere or running water. The strongest example of a malarious locality one might make would be in suggesting a marshy valley in a tropical climate, so overrun with fixed water as to destroy a prolific vegetation, yet not covering it enough to protect the garbage from the putrefying influences of the sun; this valley, in turn, so environed with hills as to shut off a circulation of air….Ground newly broken is not unapt to generate miasm. This results from the sudden exposure of long-buried vegetable matter to the influences of moisture and heat….It may readily be conceived that malarious situations exist where the miasm is not sufficient in quantity to produce the effects of intermittent or bilious fever, yet where there is quite enough of it to keep a man feeling good for nothing,—he is not sick, but he is never well. I know of one country seat of this kind, where forty thousand dollars would not pay for the improvements put upon it, and where, I am free to declare, I would not think of living, even if, as an inducement, a free gift were made to me of the place….Besides miasm, there are other atmospheric associations to be considered. I recall this moment a distillery, where attempt was made to get clear of the mash by throwing it into a running stream, with the anticipation of its being carried to the river, but where, on the contrary, it became a stagnant putrescent mass, impregnating the air for miles with its unendurable odor, and inducing such a typhoid tendency that half the countryside were down with fever….There are, again, situations where the filth and debris of sewage exercise a poisoning influence on the surrounding atmosphere. This has its principal application to the neighborhood of cities and towns drained into adjoining streams. London and the Thames furnish a notable illustration. A cove, attractive as it is, may prove a receptacle for the accumulation of dead fish and other offal, which shall make untenable the charming cottage upon the bank. A deep cove has rarely healthy surroundings, the circulation of its water being too sluggish to insure freshness and vitality. Water, like blood, to be healthy, must be in a state of continuous movement.

A nonobservant man, purchasing a beautiful stream, may be completely disappointed by finding that the opacity of its water depends upon a factory, of which he had never so much as heard; he may not let his children bathe in it, for he may well fear for them the fate of the fish he so plentifully finds lying dead upon the shore. A poisoned rural stream is as sad a sight as it has grown to be a common one. Always, before buying water, know what there is up stream, or what there is likely to be.

Never buy a country house without seeing to it that the foundation stands upon a higher level than some channel which may drain it, and this, by the way, is not to consider alone the dry summer day on which you go first to visit the place; you are to think of the winter and spring. Look to it that no excess of water shall be able to drown you out; some places, which in dry weather are glorious, are, in winter and spring, ankle deep in slush and mire, and everything about them is as wet as a soaked board. Open the front door of such a house, and a chill strikes you instantly. A fire must be kept the year round, or otherwise you live in the moisture of a vault. Places there are of this class where the question of the water from the kitchen pump comes to absorb the attention of the whole household.