Once occupied, the most important thing in the house is fresh air. The most common impurity in the atmosphere of rooms is carbonic acid gas, which is thrown off by the lungs of the occupants, and must be disposed of by ventilation in order that health shall be assured. The lamps or gas lights used in the room likewise give off carbonic acid, which is formed at the expense of the oxygen of the air, the vital element, which we require to breathe. Crowded rooms, or any rooms improperly ventilated, become tainted in this manner, and the headaches and faintness which we experience under such circumstances are direct and natural results of carbonic acid poisoning. School rooms are particularly trying upon pupils and teachers, unless their ventilation is especially guarded. It is considered that the proper degree of purity in the air of a room can be maintained only by introducing at least 2,500 cubic feet of pure air per hour for each person, this being a virtual minimum. In mines it has been noticed that the men require not less than 6,000 cubic feet per hour, and that when the quantity falls to 4,000 cubic feet there is a serious falling off in the work done. Manifestly the better and tighter the building the more need there is for special means of ventilation.
In the days when open fireplaces were almost the only means of heating houses they were of great value in aiding ventilation. Nowadays our stoves, radiators and furnaces do not help us in this matter, and we must take additional pains to see that ventilation is provided in some other way. Of course the simplest and most perfect method is to permit the free passage of the wind through open doors and windows. Every room should have its air thus completely renewed at least once a day. The mere renewal is done in a few minutes, but a longer time is required to dislodge the organic vapors and other impurities that lurk in the corners and behind furniture. In schools and work shops this should be done during the intervals for meals, and in churches between services. But in our climate it is not possible to have windows and doors open during all the time a room is occupied, except in very warm weather. It is seldom, however, that the window of a bedroom cannot be opened for a few inches all night without direct benefit to the occupant of the room. His bed, of course, must not be immediately in the draught. Curved pipes, ventilating shafts and slides under the windows are substitutes easy to use when windows cannot be actually opened.
GUARD YOUR WATER SUPPLY
Water supplies differ greatly in purity and composition, and are of the utmost importance in their effect upon the general health of a household. There is nothing which requires to be guarded more carefully. Absolutely pure water is almost unknown. Rain water collected in open countries is the purest, though even it takes up matters in its passage through the air, and in towns may be strongly acid. All waters which have been in contact with the soil dissolve out of it numerous inorganic and organic substances. Waters are described as hard or soft, hardness being the popular expression for the property of not easily forming a lather with soap. It is due to the presence of salts of lime and magnesia. Hard waters, if their hardness be not excessive, are agreeable and wholesome for drinking, but not well adapted for laundry or bathing purposes. They tend to harden vegetables cooked in them, and do not make as good tea as soft water. Rain water is, of course, the softest, but as a rule lakes yield waters also quite soft. When a good and wholesome water cannot be obtained from springs or rivers, as in malarial districts, and when there is reasonable ground for thinking the ordinary sources are contaminated by epidemics, it is well to fall back on the rainfall for drinking purposes, with special care that it is collected in a cleanly manner.
Surface wells are always to be viewed with suspicion when they are in the vicinity of stables and cesspools, farm yards, cemeteries and anywhere in the towns. The filtration of the water through the soil removes the suspended matters, so that it may be clear enough to the eye, but it has no power to remove impurities actually dissolved. The eye cannot be trusted to judge the impurities of drinking water. Water which appears absolutely clear may be unwholesome in the extreme, and water with sediment floating in it may be in no way unwholesome. Nothing but an analysis of the water can settle this with absolute certainty. Deep wells and artesian wells which penetrate the surface strata are likely to be safe. Marsh waters carry malaria and should never be drunk without boiling. Indeed suspicious water of all sorts may be made safe by boiling, although it is not sufficient always merely to bring it to a boil. Thirty minutes above the boiling point is a safe rule to follow. Typhoid, diphtheria, dysentery, cholera, diarrhea and other dangerous diseases are caused by impure water, either by suspended mineral matters acting as irritants, by suspended vegetable and animal matters, or by dissolved animal impurities. Sewer gases dissolved in water, in addition to these diseases, cause sore throats, boils and other ailments.
It must not be forgotten that water closets, stable yards, manure piles, decaying kitchen slops and all sorts of filth are responsible for many of the most serious diseases, either by draining into the well and so contaminating the water supply, or by direct breeding of disease germs carried as dust and inhaled. Health is one of the rewards for household cleanliness of the most careful kind.
HOW DISEASES ARE CLASSIFIED
In one sense most diseases are preventable, if all the circumstances which tend to spread them could be absolutely controlled by a single wise authority, and if all the physiological laws would be obeyed by all persons at all times. But as this happy condition is not in effect, we have to reckon with various kinds of diseases, as well as the accidents and injuries which come to us in health. The various diseases are classified into general groups.
Endemic diseases are those which are constantly present in a community because of certain unfavorable conditions, such as malaria in swampy regions, rheumatism from bad climatic conditions, and diseases resulting from unhealthy employments. Miasmic diseases are those due to conditions of the soil, and comprise the various forms of intermittent fevers, agues and the like. Infectious diseases, on the other hand, belong to the people, and not to the place. They are communicated from one person to another through the air, or by means of infected articles of clothing, etc., and they attack the strong and healthy, no less than the weak. Among such are smallpox, scarlet fever, measles, etc. Various branches of infectious diseases are recognized in addition, as combining some of the characteristics of the classes already named. For instance, erysipelas and other blood poisons are generated with the body of the individual who, so to speak, infects himself and may then infect others. Typhoid, cholera and yellow fever are miasmic diseases, but they are also capable of being carried by human intercourse, infected clothes, polluted water, etc., within certain limits of space and time. Hydrophobia, glanders and such diseases are communicated only by actual contact of body. Rickets and scurvy are preventable, though not communicable diseases, being direct results of mal-nutrition or imperfect nourishment, and consequently are diseases of diet.
Bacteria are those minute organisms which under various names are the active causes not only of diseases but of all putrefaction, fermentation and like changes in dead organic matter. Like all living things they may be killed, and on this is based the whole theory of disinfection. Some are more hardy than others, under conditions which are frequently supposed to be unfavorable to them. Merely to destroy an unpleasant odor or to admit fresh air into a room does not mean to disinfect, and it is necessary to understand this clearly in the effort to purify rooms in the event of infection.