Read Ebook: Hand-book of Sanitary Information for Householders Containing facts and suggestions about ventilation drainage care of contageous diseases disinfection food and water. With appendices on disinfectants and plumbers' materials. by Tracy Roger Sherman
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some other gases. Such mixtures are sometimes found in long-closed cesspools and privy-vaults, but not in sewers proper.
Of these gases, sulphureted hydrogen and carbonic acid are very poisonous, and when they are inhaled in concentrated form produce almost immediate unconsciousness, and often death. When less concentrated, sewer-air may cause nausea and vomiting, followed by a low fever which sometimes kills, and, if not, results in a tedious convalescence. As a rule, it is so largely diluted that it produces no immediate effects, excepting the discomfort due to offensive odor, and the mental anxiety resulting therefrom.
There also seems to be a connection, imperfectly understood, between bad drainage and malarial fevers, and perhaps cerebro-spinal meningitis.
The origin of yellow fever is not yet ascertained.
Surgical erysipelas, puerperal fever, and hospital gangrene, are only developed on and about wounded surfaces, and seem to be due to the organisms developed in the secretions of such surfaces, where ventilation and drainage are bad.
VENTILATION.
The contamination of the atmosphere by the respiration and bodily emanations of human beings and other animals is unavoidable, but the noxious matters thus added to the air are being constantly changed in the following ways:
It is necessary, for the proper purification of a contaminated atmosphere, that it should be largely diluted with fresh air. Hence arises the need of the constant change of air in dwellings.
Air expands when heated and so becomes lighter. Local differences of temperature, created by natural and artificial means, therefore bring about currents in the atmosphere, the cooler and heavier column of air always descending, and the warmer and lighter always rising. This fact is taken advantage of in ventilation.
It has been estimated that, to keep the air pure, three thousand cubic feet of fresh air per hour are required for a male adult, and that a sleeping-room should contain at least twelve hundred cubic feet of air-space for each occupant.
When the temperature of the external air is such that the doors and windows can be constantly open, they afford the best means of ventilation for dwellings. An exposure to draughts, however, is dangerous to many persons, and it is desirable, therefore, in cooler weather, to devise means of admitting fresh air without creating a draught. At a temperature of 60?, a draught is perceived when the air moves at a higher rate of speed than three feet a second. Now it is obvious that a draught may be rendered harmless if the entering current of air is guided in such a direction as not to strike the occupants of a room. This is accomplished simply and cheaply by either of two devices: If the lower sash of a window is raised a few inches , and the space between the bottom of the sash and the window-sill is filled by an accurately fitted board, there will be a space between the panes of the two sashes, through which air will enter, spouting upward toward the ceiling and not falling until its momentum is so much diminished that it will not be felt as a draught. The other plan is to make the upper portion of the upper sash movable, so that it can be tilted inward at such an angle as to direct the entering current upward .
There are various patent apparatuses for the admission of fresh air through windows without draught, but they are mostly modifications of the methods above mentioned.
In weather when artificial heat is necessary for comfort, thorough ventilation is not difficult, provided expense is not considered. As the removal of the foul air, however, involves a considerable waste of heat and consumption of fuel, the means of procuring the best ventilation at the least cost becomes a problem of great intricacy, which has not yet been satisfactorily solved.
Modern fireplaces are sometimes built with a metallic flue extending upward into the chimney. Between this flue and the masonry is an air-chamber opening to the external air and communicating with the room near the ceiling, so that fresh air from outside the house is continuously warmed, and discharged into the room at a temperature of 80? or 90?. The Galton fireplace is of this kind, and utilizes 35 per cent. of the fuel.
The best combined heating and ventilating arrangement at present seems to be that which warms the fresh air by means of a soapstone furnace or steam-coils, and removes the foul air through a fireplace. In milder weather, gas may be burned in the chimney at a slight expense. According to Morin, seven cubic feet of gas burned in a flue eleven inches square and sixty-six feet high, will draw thirteen thousand three hundred cubic feet of air per hour from a room.
The common whirling ventilators in window-panes are of very little use.
As a rule, fresh air should enter a room near the ceiling, and foul air be removed near the floor.
In very cold climates, dangerous draughts are often produced by the cooling of the air in contact with the window-panes, so that it falls and sweeps along the floor. This danger may be prevented by double windows, which also save fuel. Double windows may be utilized in ventilation, by raising the lower outer sash a few inches, and lowering the upper inner one.
DRAINAGE.
There is no evidence to show that the emanations from fresh house-slops, or the excreta of healthy animals, are injurious to health, but it has been proved that when these matters decompose they become dangerous. The bubbles of gas which rise to the surface of such decomposing matters, when they burst, throw up solid particles of organic matter in the air, which float about for some time before falling to the ground. It is, therefore, essential to health that all such matters shall be removed from the vicinity of human beings promptly, before decomposition sets in, or else so manipulated as to prevent decomposition, or promote rapid oxidation.
The lower animals seem to recognize by instinct that their excreta are dangerous, and they deposit them in places remote from their abodes, or else carefully cover them with fresh earth. Man alone retains his excreta in carefully prepared receptacles near his place of residence, until the accumulation is so large that he is forced to remove it.
Its disinfectant properties have been shown to be due to the presence of microscopic organisms, which decompose the excreta in the act of nourishing themselves. A little chloroform paralyzes them, and deprives the earth of its disinfecting properties, which return, however, when the chloroform is washed out, and the organisms recover their natural vigor.
The earth for these closets must be dry, and sifted of coarse particles, and enough must be deposited upon the excreta to cover them and to absorb the urine.
Its advantages, as compared with the water-closet, are, that it is cheaper, requires less repair, is not hurt by frost, is not injured when improper substances are thrown down it, and requires no water. Its disadvantages are, the trouble of collecting and drying the earth, the necessity of frequently removing the soil, the dust sometimes caused by its use, and the necessity of providing additional means for the disposal of slops.
The water-carriage system includes bowls or sinks for the deposit of refuse matters, connecting-pipes to remove such matters from the house, and public sewers for their further conveyance away from human abodes. The construction and care of public sewers belong to the local government; we have here only to do with house-drainage.
The essentials of house-drainage are: 1. The primary receptacles should be of such material and so constructed as to be impervious to fluids, and easy to clean and keep clean. 2. The pipes should be of such material as to be as durable as possible, and so laid and connected as to form gas-tight conduits, and to insure the rapid passage of whatever enters them, so as to prevent the formation of deposits or incrustations. 3. The drainage system should be so planned and constructed that neither the atmosphere of the house nor the drinking-water can be polluted by anything escaping from it, and no noxious matters can enter it from any other house.
The following plan of construction is that recommended by the Board of Health of New York city:
Shafts not less than three feet square in area are required in tenement-houses, to ventilate interior water-closets.
Traps are of various kinds, and many are patented. The accompanying figures represent the principal types.
A few patent traps are shown as samples:
Fig. 12 is the Adee trap, a modification of the D-trap. Fig. 13 is the Bower trap, claimed to be secured against siphonage or back pressure by a rubber ball which floats up against the entering-pipe. Modification of the bottle-trap. Fig. 14 is Bedell's trap, with a metallic flap or valve, and an opening on the sewer side of the valve, to relieve pressure. Fig. 15 is Stewart's trap, intelligible from the diagram. Traps are also made of iron or glass, with a mercury seal, which, it is claimed, are proof against siphoning, pressure, or evaporation.
A water-closet, to be well flushed, should have a discharge of three gallons of water in five seconds, sent directly downward all around the rim.
Fig. 25 shows a system of house-drainage for a city house planned in accordance with the above rules.
If water-closets are used, the following system is recommended in "The Sanitary Engineer": Collect all the sewage of the house in a small and perfectly tight tank or cesspool, in which the paper and fecal matter soon become macerated by fermentation and reduced to a pulp. This tank should overflow into the flush-tank, the overflow-pipe dipping at least a foot below the point of discharge, to avoid the scum. The siphon of the flush-tank should be accessible by a man-hole, so as to be readily cleaned. If thus arranged, and if no roots of trees are in the soil, the distribution-pipes will not clog for a year or more, sometimes not for ten years.
Pipes should be laid at a depth of eight inches, with a slight and uniform descent of not over six or eight inches in one hundred feet. Branches from a four-inch main to the two-inch distribution-pipes should lead from the bottom of the former, instead of from the side, as in ordinary drain connections.
There should be a grease-trap attached to the kitchen waste-pipes, in order to prevent clogging of the tanks and pipes by the congelation of fat.
If there are two traps on the same line of pipe , so that a part of the interior of the pipe is cut off from the external air in both directions, it becomes "air-bound," and one of two results will follow, viz.: water discharged into the fixture above the higher trap will remain in the bowl and not run down, on account of the compression of air between the traps; or, if it does run out of the fixture, it will displace an equivalent bulk of foul air, which will bubble up through the upper trap and cause offensive odors. In such a case, the lower trap should be removed.
When a body of water sufficiently large to nearly fill a pipe is discharged into it, it drags air along with it, and exhausts the air in all branch-pipes to a greater or less extent. When this exhaustion amounts to a diminution of the pressure in the pipe of about 1/350, the water in an ordinary trap will be forced out of it by the pressure of the external atmosphere, or in other words will be sucked out of the trap into the pipe, leaving no water-seal in the trap, and, therefore, allowing free exit for sewer-air. This effect is known as the "siphoning" of the trap, and is most likely to occur when the main pipe is not open at its upper extremity , and when the branch wastes are of the same size with the main one. This fault is remedied by the ventilation of the traps, and of the main pipes, as described in the regulations above quoted .
If the object of an examination is to determine whether the drainage is planned and constructed in accordance with the best methods of the day, each point referred to in the above regulations should be carefully investigated.
If the object is to determine the source of offensive odors, or if there has been sickness in the house of such a character as to indicate possible defects in the plumbing, the several sources of bad odors just enumerated should each be carefully inquired into. A few additional suggestions as to the method of examination will not be out of place.
It will be found much easier to determine the direction, number, and situation of the main lines of pipe, if the examination is begun at the roof and continued downward. If a beginning is made in the cellar, confusion results.
If a trap is accessible, it is easy to determine whether its water-seal is preserved or not by tapping it from top to bottom with some metallic substance, when the difference in sound will indicate the exact level of the water inside.
Those parts of the plumbing which are not accessible to inspection must be examined by introducing into the pipes some strong-smelling substance, which will indicate defects by its escape through them into the house. Oil of peppermint is often used for this purpose.
It is best to introduce the oil into the pipes from outside the house, if possible, so that the odor which inevitably attends the process may be dissipated in the external air. The object being to ascertain the location of defects in the pipes inside the house, the examiner must feel certain, if he detects the odor of peppermint anywhere, that the vapor has come to him from inside the pipes, and not from the outside. If the ventilating-pipes are so constructed that the oil can not be poured in from the roof, then it must be poured into some basin or water-closet in the upper portion of the house. The peppermint should first be mingled with a pailful of hot water to promote rapid volatilization, and poured slowly down the pipe. After it is poured down, the openings at the upper extremities of the pipes should be closed, so that the pressure of the vapor inside the pipes may not be relieved in that direction. If the odor of peppermint, thus introduced with the precautions mentioned below, is perceived anywhere in the house, it is an indication that there is an opening in some pipe, through which sewer-air may escape. This opening may be a defect, or it may be due to siphoning of traps, or to faults of original construction. There will not usually be much difficulty in locating it with considerable exactness.
The peppermint should be kept on the roof, or on a window-sill outside the house, until needed, for it is so volatile that the vapor escapes through the cork, and if the odor gets into the house in this way, it will vitiate the examination.
The person who pours the peppermint should remain on the roof or in the room where he does it, with the doors closed, until the examination is complete, for the odor will cling to his clothing and follow him wherever he goes for an hour or more.
If bad odors have been noticed, and no defect can be found in the ways above mentioned, they may be due to decaying animal matter , or to defects in the plumbing of the adjoining house, offensive gases from which may penetrate the wall.
The source of bad odors need not necessarily be in the immediate vicinity of the place where they are noticed, for the walls of buildings are full of channels and openings, through which offensive gases may be carried by currents of air, so as to emerge at a considerable distance from their origin. Thus, in winter, they are apt to be most noticeable near a fire.
SUMMARY OF THE BEST METHODS OF DRAINAGE.
Have the house separated from the soil on which it is built by a layer of asphalt between two layers of cement, extending over the whole cellar-floor, through the foundation-walls and up above the point where the ground touches the walls outside. Or have the house built without a cellar, and with perforated underpinning, so as to allow a free circulation of air underneath it. The subsoil should also be drained by tiles laid at least a foot lower than the cellar-bottom.
The cold-air boxes of furnaces should draw their supply from the external air. It is advisable to have a thin layer of cotton held in place by wire gauze to filter the air as it enters them.
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