A system of practical medicine. By American authors. Vol. 1

by Unknown

DRAINAGE AND SEWERAGE IN THEIR HYGIENIC RELATIONS.

BY GEO. E. WARING, JR.

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For reasons, sometimes sound and sometimes fanciful, the drainage question often presents itself to the medical practitioner as an annoying if not as a serious one. It is not necessary for the physician to make himself an adept in the art of sanitary drainage, but he can properly meet neither the demands of nervous patients nor the exigencies of sometimes serious situations without having an intelligent general idea concerning it. Not only to prescribe improvement, but frequently to allay ill-grounded apprehension, he should be able to address himself, intelligently and promptly, at least to the few simple problems presented in connection with ordinary houses. I use the expression "ill-grounded apprehension," not because the drainage in and about houses is generally tolerably good, for it is not, but because the race seems to have so inured itself to certain grave defects in plumbing-work that one may reasonably hesitate, and look elsewhere for the occasion of diseases before accusing the imperfect sanitary appliances of an average house.

Anything like a treatise on the technical details of house-drainage would be quite out of place here. There are note-books easily accessible to such physicians as care to make a thorough study of the subject. It does seem worth while, however, to pass in careful review, in a work of this character, the various conditions of interior and exterior drainage upon which a physician is frequently called to pass judgment.

The perfect drainage of a house, like the perfect drainage of a town, implies the immediate and complete removal, to a point well beyond its limits, of all waste matters which are a proper subject of water-carriage; such a thorough ventilation of the channel which these matters have traversed as to reduce to a minimum the production of deleterious gases arising from the decomposition of the film with which they may have soiled the walls of their conduit; and adequate provision for the absolute and permanent exclusion from the atmosphere within the house of the air of the pipe or sewer. This is a brief and simple statement of the fundamental and absolute requirements of all good drainage. It is founded on the one grand object which governs all improvement of this character: the prevention of decomposition of refuse matters anywhere in house or town.

Practically, it is safe to say that these conditions are never complete, and that instances of perfect work are so exceptional as to need no consideration here. We have to assume, substantially in every case that is presented, that we are dealing with defective work, ordinarily with work that is very seriously defective. Most houses have been built by contractors, and the plumbing is perhaps the item of the whole structure that it is considered easiest and safest to scamp or to neglect. Even where the motive of economy has had no controlling influence, the drainage has almost invariably been planned by a plumber who has learned his trade and conceived his ideas in the performance of work which was done at a time when no one realized the serious consequences of its being improperly done. The absence of interior ventilation, leaky joints, ill-arranged connections between the various plumbing appliances and the main outlet from the house, pipes and traps so large that an ordinary current is powerless to keep them clean, defects of form, defects of material, and defects of construction, are met with on every hand. This general statement is of itself sufficient to show how hopeless it is for the average physician to prescribe the manner in which the drainage of a house should be constructed or remodelled.

If we view the question solely with reference to its bearing on the causation of disease, we enter a field where neither the sanitarian nor the physician is ever sure of his footing. The precise relation between bad drainage and ill-health no man knows. Certain diseases are undoubtedly traceable to conditions of air or of drinking-water due to the improper disposal of organic wastes, but the extent and exact bearing of these influences are still greatly a matter of conjecture. It is, however, undoubtedly safe to assume—and the assumption is supported by ample general observation, if not by precisely ascertained facts—that whether we are considering serious diseases or the slighter ailments, every argument leads to the enforcement of the most strenuous requirements of cleanliness. Through all the ages no one has disputed, and no one has improved upon, the simple sanitary formula, "Pure air, pure water, and a pure soil." We may safely wait until the enthusiastic investigators now engaged with the subject shall have adduced the testimony of positive facts, if we will in the mean time adhere strictly to the requirements of Hippocrates' prescription. The physician will surely not go wrong if he treats all obvious defects of drainage as positive evils, and insists upon their complete reformation.

Not to confine ourselves to houses which are provided with the ordinary modern plumbing-works, but to include all collateral branches of the subject, we have to consider the following conditions:

I. THE REMOVAL OF HUMAN EXCREMENT:
	(a) By water-carriage in houses provided with modern plumbing;
	(b) By some form of dry conservancy;
	(c) By the fiendish privy-vault which prevails so generally, save in the larger cities.
II. THE REMOVAL OF LIQUID HOUSEHOLD WASTES:
	(a) By delivery to public sewers;
	(b) By irrigation disposal;
	(c) By delivery into cesspools.

Incidentally to the above there must be considered the influences of the ultimate disposal of all household waste, whether by the public sewer or the private house-drain.

I. THE REMOVAL OF HUMAN EXCREMENT.—We are too apt to judge of the power for mischief of any waste matter by its original offensiveness, and the world at large regards the solid and liquid exuviæ of the human body as the most dangerous material with which it has to deal. Doubtless it is so under certain exceptional circumstances. If impregnated with the infective principle of cholera or of typhoid fever, for example, its influence for evil may be widespread and active, but in the absence of such infection these substances offer a less serious problem, and, as their offensiveness causes them to be more carefully avoided, their evil influence is less, and is less widely disseminated, than is that of the comparatively inoffensive wastes of the kitchen-sink. This is a consideration important to be borne in mind. Nothing is more common than the expression of the opinion that the wastes of a population are offensive and dangerous in proportion to the degree to which excrementitious matter is allowed to flow away with its general drainage. The fact is, that the drainage from a house or from a town, if reasonably diluted with water, is very slightly offensive until it has passed through a considerable degree of decomposition. The outflow of a perfectly sewered town, where the whole community uses water-closets, is less offensive than the neglected back-yard drain of an average New England farm-house. The trouble begins with the condition of putridity. Fecal matter and urine are somewhat quicker than the other wastes of the house to enter into putrefaction, but the difference is only one of degree, and the latter rapidly overtakes the former in the foulness of its condition; so that where a house is provided with two cesspools, one for water-closet matter and the other for kitchen waste, it is quite impossible to determine from the character of their contents which is which; therefore examinations of the drainage of a house should by no means be confined to the manner in which its excrementitious matters are disposed of. Setting aside, in this connection, the peculiar liability of these matters to become the seat of specific infections, it is fair to assume that equally complete and cleanly arrangements are needed for all else that flows to waste, as for the discharges of the water-closet. The purpose of these remarks is of course not to belittle the importance of proper care in the disposal of human excreta, but to prevent the giving of an undue importance to this branch of the subject, with too light treatment of the very serious difficulties presented by the others.

(a) Modern conveniences may fairly be said to be the bane of modern society, or at least of such of its members as have the questionable good fortune to be housed within the same four walls with every device that a misguided talent for invention has led the American mechanic to provide for the comfort and convenience of the occupant. Properly regulated, there is no element of modern house-building more conducive to health than such a system of plumbing as brings within reasonable limits the labor of supplying abundant water at every point in the house, and obviates the need for exposure and removes the temptation to neglect and postponement attending the use of out-of-door houses of convenience. The spigot and the water-closet are the two essential sanitary agents which the plumber offers to us. The bath may be replaced by the sponge, the stationary wash-basin may be, and generally should be, replaced by the bowl and pitcher of our fathers, but there is no sufficient substitute for an ample supply of water on each floor of the house and for a cleanly water-closet placed within doors. The evil that the plumber has inflicted upon the race is due very largely to his not having held his hand when he had fairly provided for our reasonable requirements. When he fills our bedrooms with stationary basins, connects our refrigerators with the sewer, provides twenty outlets for water which had better reach the drain through less than half that number, and incidentally underlays all our floors with pipes, every foot of which is a possible source of danger, he turns what ought to be a blessing into what is too often an unmitigated curse.

It will not be easy to convert persons who have become accustomed to the universal diffusion of plumbing-works throughout the house to a belief that their best sanitary interest, and, perhaps hardly less, the best requirements of refinement, point to the abandonment of what is practically superfluous in the way of wash-bowls, bidets, foot-baths, sitz-baths, urinals, etc.; but one who has given careful attention to the subject cannot hesitate to recommend that in a house which is "strictly first class" it would be the part of wisdom to reduce by at least three-fourths the openings which lead to the soil-pipe and drain and sewer, and to concentrate upon the remaining fourth the flushing effect of wastes which are now so widely distributed. Strenuous effort is being made, not only by those who write and talk in the interest of the plumber and manufacturer, but by many who honestly believe that the good the plumber has to give us cannot be given with too free a hand, to prove that so long as they are properly constructed and properly arranged we may use plumbing appliances at every point in the house with the utmost freedom and with a minimum of danger. The minimum of danger, and often more than the minimum, does, however, exist. It exists, perhaps, in a constantly increasing degree with every extension of the work, and it can only be the part of wisdom to insist, so far as advice can have influence, on the reduction of all these appliances to the least requirements of reasonable comfort and economy of labor. My own advice would be, in all cases, to permit the use of no wash-bowl or bath or other vessel at a greater distance than a few feet from a vertical soil-pipe, and not to permit their use in any case in bedrooms or in closets opening only into bedrooms.

At the risk of seeming extravagant, I would say that the stationary wash-bowl as ordinarily used is one of the most uncleanly of modern household appliances. Long experience in the inspection of houses and in the examination of waste- and drain-pipes has led me to the belief that servants, by no means rarely, use these vessels as the most convenient means of voiding and cleansing chamber utensils. Their overflow-pipes are coated with soap and with the exuviæ of the skin to a degree which makes them usually the seat of an offensive decomposition. Their plugs and chains are almost invariably foul, and those devices which provide for closing the outlets by valves or plugs, somewhat removed from the strainers at the bottom of the bowl, bring the water in which the face is washed into an interchanging communication with a considerable length of foul and uncleanable waste-pipe—a communication that is made active by the bubbling of the contained air as the pipe fills with water. The labor of filling pitchers from a spigot on the same floor, and the labor of emptying chamber-slops into a water-closet on the same floor, are not to be considered as compared with the greater cleanliness and the greater sanitary security that such an arrangement ensures. There is no serious objection to the placing of wash-basins and baths in the same apartment with the water-closet, or elsewhere immediately adjoining the soil-pipe; but it certainly cannot be disputed that the extension of the drainage system by horizontal lead pipes to remote points is altogether and wholly to be condemned.

However, the question more immediately at hand is that of the disposal of human excreta by the use of water-closets; and it is the water-closet that first attracts the attention of one who is called upon to examine the sanitary condition of the work. There are several radical defects in water-closets, which are so widespread and which have become so familiar to the world at large as to attract less attention than they deserve. For example, it is a radical defect of a water-closet to be tightly encased in carpentry. Nearly all the water-closets now in use have a somewhat complicated mechanism about their bowls. They consist in part of earthenware and in part of iron, generally with an unstable connection between the two. More often than not they overflow or drip or leak, and whatever may escape from them, whether foul air or foul water, is confined within an unventilated space, but a space which is still not absolutely excluded from the atmosphere of the house. The removal of the "riser" or vertical board under the front of the seat will usually disclose at once a condition that suggests at least the need for thorough ventilation. It also discloses in some cases a complication of machinery and pipes and levers and chains which makes a thorough dusting and cleansing of the space difficult, even were it accessible. There are water-closets which are essentially good in their construction and working, which it is important to protect by a "riser," but this "riser" should never be of close work. It should at least be freely perforated with large holes, or, better still, be made with slats or blinds, so that there may be the freest possible circulation of air under the seat. If there is an entire absence of machinery, so that the whole space may be left open, being well finished with tiles or hard wood or other suitable material, it is better that it should be unenclosed and that the seat should be hung on hinges, so that it may be turned back, exposing the whole space to easy cleansing. It is better too, in all cases, that the ventilation should not even be interfered with by a cover over the seat, the freest possible exposure to the air being of great importance.

A very large majority of the water-closets in use throughout the world are either very imperfectly flushed "hoppers," which are generally foul and which are often defective in their traps, or that worst of all forms, known as the "pan" closet, where a slight depth of water is held in the bowl by a hinged pan closing over its outlet. This pan swings in an iron chamber under the bowl, which is entirely cut off from ventilation, which is generally foul with adhering fecal matter, and which as an abomination has no equal in the whole range of plumbing appliances. The closet of which it forms a part has everything to condemn it, and only its cheapness and its apparent cleanliness, and the habit of the world in its use, to commend it. If flushed, as it usually is, by a valve on the supply-pipe, it is rarely flushed adequately, and its use not seldom leads to an indraft of foul air (or worse) into the main water-supply system of the house. Such closets may be easily inspected as to their condition by shutting off the water-supply, opening the pan, and lowering a candle into the container below. Such an inspection will almost invariably disclose an extremely and dangerously filthy condition. Yet the worst part of the container, that which never receives an adequate flush, is even then concealed from view by the pan being thrown back against it. The nose will here be a good adjunct to the eye, and the odor escaping from this filthy interior chamber will generally afford convincing testimony of the impropriety of allowing such a vessel to remain in use.

It is a rule almost without exception that closets, except perhaps on the first floor of the house, which are flushed by valves connected with the bowls, are to be condemned. However good or however bad the state of a closet thus supplied with water, its condition will always be improved by giving it a copious flush from an elevated cistern delivering never less than two and a half gallons of water at each use, and delivering it through a pipe so large and so direct as to secure a thorough cleansing at every discharge.

It would be out of place here to enter into a detailed description of the various closets which are and which are not to be recommended for use. So far as the physician's inspection is concerned, it is perhaps sufficient to say that wherever an odor, however slight, can be perceived, and wherever a fouling of the interior surfaces of the closets or of the spaces under the seat can be detected by the eye, radical reformation is necessary. The only safety with a water-closet, as with any other vessel connected with the drainage of the house, is to secure an immediate and complete washing away of all foul matter of every kind. Where this result is not attained, it should be insisted upon. This much lies within the province of the medical attendant; the manner in which it shall be secured is not necessarily for him to decide.

One other branch of this subject is worthy of attention. The cleanliness and freedom from offence of the water-closet or of a waste-pipe or drain is in proportion to the frequency with which it is used and to the abundance of the discharge of water through it. A dozen closets used by a dozen persons will be quite likely all to be offensive. If the dozen persons all used only one closet—not a pan closet—the frequency with which its trapping water is removed and the frequency with which its walls are washed would secure its tolerable condition, even if not of the best construction. In this case, as in all others, simplicity should be the controlling principle.

(b) Dry conservancy next after water-carriage is the best and safest system for the removal of human excreta. By dry conservancy is meant the admixture of dry earth, ashes, or similar material with the matters to be disinfected and absorbed. Theoretically, the effect of such admixture is entirely satisfactory; under very careful and intelligent regulation it is practically so. It has been proved, however, by much experience that under ordinary circumstances—that is, where no greater care is given than is ordinarily given to a water-closet or to a common privy—the dry conservancy system is open to serious objections, though always an improvement on the cruder privy-vault. The theory of the effect of a sufficient admixture of earth or ashes with urine and fecal matter is, that by the admission of air thus secured to every part of the material there is a complete oxidation of their organic constituents, similar to, though slower in its operation than, actual combustion in an active fire. In isolated houses and in hospitals, factories, and other buildings not provided with sewerage facilities, there is no question that the earth-closet or the ash-closet affords the best available means for disposal, if we except a system, to be described hereafter, for the distribution of water-carried wastes over or under the surface of suitable ground.

Incidentally—and this is of special interest to the physician—the use of dry earth or of dry ashes in the close-stool of the sick chamber effects not only an immediate and complete deodorization, but without doubt a complete disinfection as well. A quart of dry earth at the bottom of the vessel to receive the deposits, and rather more than a quart with which immediately to cover them, constitutes a means of relief always available and always efficient.

Where the house is provided only with an old-fashioned out-of-door privy the greatest relief and the most complete security may be given at little cost by filling the vault, and placing under the seat a movable box to receive the mixture of fecal matter and of the absorbent material, which, if it is desired to avoid the simple patented appliances made for the purpose, may be kept in a box or barrel in the apartment and thrown down after each use of the closet with the hand-scoop. The objections to the common privy are so obvious, so universal, and so well understood that the practical value of such a means of relief should be appreciated without argument.

(c) Privy-vaults are the sole reliance for the disposal of fecal matter, and often of chamber-slops, of probably 95 per cent. of the population of this country, and of Europe as well. It is curious, in examining the recommendations of public health officers and the requirements of local boards of health, to observe the uniformity with which this most important subject is passed over with the prescription that the vault shall be tight, sometimes that it shall be vaulted over, and sometimes that it shall not be within a certain small number of feet of a boundary-line or of a drinking-water well. These prescriptions are most absurd. It is safe to say, that of the millions of privy-vaults in this country not more than hundreds are really tight; that a still smaller number are so vaulted over as to prevent the free exhalation of the gases of decomposition; that those which are so vaulted over are in all respects of worse sanitary effect than those which have freer communication with the air, and that their possibilities of evil reach many times farther than the limits of distance usually required to intervene between them and the well or the neighboring property. In view of the universality of their use and of the completeness with which modern communities are inured to their presence, it seems almost hopeless to attempt to secure a proper realization of their great defects. They are always the seat of the foulest, and even of the most dangerous, decomposition. They taint not only the air and the soil, but the water of the soil which goes so often to feed our sources of drinking-water, and their local stench is of itself sufficient to sicken all who have not by daily and lifelong habit become accustomed to it. Taking the country at large—farm houses and village houses as well as the dwellings of cities—it is not too much to say that the best sanitary service that can be rendered by those interested in the removal of causes of ill-health would be in securing the abolition of these barbarous domestic appliances. In many ways the cesspool is as bad as the vault, but in some respects the vault is facile princeps as a public and private nuisance of the most annoying and dangerous character. Wherever a public or private sewer is available, wherever disposal by irrigation is possible, and wherever even the crudest attention can be secured for an automatic or simpler earth-closet, the strongest effort should be directed to the absolute inhibition of the common privy-vault.

II. THE REMOVAL OF LIQUID HOUSEHOLD WASTES.—As has been stated above, the liquid household wastes are of much more serious consequence from a sanitary point of view, as compared with excrementitious matters, than the public has been wont to suppose. These, owing to the large amount of water which they contain, are beyond the reach of any system of dry conservancy. They consist almost invariably of a flood of water containing but a small percentage of refuse food, urine, soap, filth of the laundry, grease—everything, in fact, except fecal matter and the coarser garbage and ashes—constituting the waste of the household. Where water-closets are used fecal matter is generally added to the flow, but its relative quantity is small, and its presence or absence does not seriously affect the problem of disposal.

In a house provided with abundant, generally superabundant, plumbing appliances, with a large consumption of water, the whole apparatus is constructed on the theory that all manner of filth is to be taken up by running water and carried well without the house. Where this theoretical end is completely attained there exists a condition of drainage rarely met with and little to be criticised. Unfortunately, the theoretical excellence is rarely secured. Running water confined within a narrow channel, and so compelled to move with force sufficient to give an energetic scouring to the walls of its conduit, may be trusted to carry with it or to drive before it pretty nearly all foreign matter that may have been contributed to it, but the moment this vigorous current is checked, that moment the tendency to excessive deposit begins. It is checked in practice in various ways:

First. By too great a diameter of the pipe: a volume of discharge requiring a velocity of 4 feet per second in a pipe 1 inch in diameter would have a velocity of only 1 foot per second in a channel 2 inches in diameter, and of less than 6 inches per second in a channel 3 inches in diameter. Ordinarily, except as the deposits are removed by decomposition (always objectionable), the deposited matters accumulate and reduce the original bore to the diameter which will secure a cleansing flow. It is the part of wisdom to provide only this bore at the outset or not greatly to exceed it, and it is one of the earliest recommendations of an experienced sanitary engineer to reduce the size of too large bores where they exist.

Second. By the use of traps larger than the pipes leading to them and from them, thus increasing the natural tendency of all traps to stagnation and deposit.

Third. By the use of vertical waste-pipes, which are almost universal, and which are very often necessary. The velocity of a current measured along the axis of the pipe is less if the direction is vertical than if it is laid on a steep slope, because of the tendency of liquids flowing through vertical pipes, which they do not fill, to adhere to the walls and to travel with a rotary movement. I have seen vertical soil-pipes furred with excrement to a thickness of nearly three-eighths of an inch; I have never seen a corresponding deposit in a pipe of good slope where the current was direct. This latter point is rather one of curious interest than of practical value—certainly from the physician's point of view. Even in original construction it is rarely possible to give soil-pipes other than a practically vertical course as they pass from one story to the next. Indeed, the physician need not trouble himself to consider the question of the size or of the direction of this main channel. He will often find occasion to criticise the use of unduly large waste-pipes from single vessels; as, for example, two-inch pipes leading from bath-tubs; two and a half-inch pipes leading from laundry-tubs; and three-inch pipes leading from kitchen-sinks. Where reconstruction is to be undertaken, he may with advantage exert himself to secure in these lateral waste-pipes a diameter never exceeding one and a half inches, and from kitchen- and pantry-sinks, whose outflow is loaded with grease, preferably not exceeding the diameter of one and a half inches, with traps of even a little less size. Where several vessels lead into the same waste-pipe these small diameters may increase the tendency to the emptying of the traps by siphonage, but if proper mechanical traps are used for baths, wash-bowls, and laundry-tubs, and if ample flushing appliances are connected with kitchen- and pantry-sinks, the temporary removal of the trapping-water by siphonage may generally be disregarded. It will seldom happen that the removal of water will be so complete as to prevent the satisfactory closing of the mechanical valve by capillarity, even if it fails, in itself, to make a perfectly tight fit.

A favorite recent requirement of theoretical sanitarians, and one which has perhaps for business reasons been eagerly accepted by the plumbing trade, is what is called the "back" ventilation of traps; that is, the carrying of a vent-pipe from every trap in the house to a point above the roof. In my judgment, there is more to condemn than there is to commend this practice, for I believe that the more rapid emptying of traps by evaporation where they are not constantly supplied by frequent use, the dangers of accident to lead pipe, which is generally used for ventilating purposes, and the misapplication of a large outlay which might better be applied in other directions, constitute convincing arguments against this favorite new method of preserving the integrity of the water-seal. There are a number of traps which are closed by floating balls, or by balls bearing upon the outlet, which seem to be quite satisfactory and efficient. The worst waste-pipes, by far, are those of kitchen- and pantry-sinks which pass a large amount of hot grease. This soon cools sufficiently to congeal, and it attaches itself to the walls of the pipe, where it does congeal until the bore is reduced to what is barely sufficient to furnish the necessary limited water-way. Grease-traps of various forms have been invented with a view to retaining this obstructing material. After much experience with all of them that have been in general use, I have become convinced that the only satisfactory way to avoid the difficulty in question is to retain the outflow of the sink until a certain considerable quantity has accumulated, and until its grease has entirely congealed, then to discharge the whole volume rapidly through a pipe of small calibre. This may be done with Carson's grease-trap by throwing in a pail of water to start a siphon action when the vessel has become filled to its overflow-point. It is more simply accomplished by a device of my own, wherein the whole outflow is retained by a plug at the bottom of a large vessel working after the manner of the plug of a wash-basin, until it is filled to the level of the sink, and then opening the outlet for its sudden discharge.

Good workmanship is as important as, if not indeed more important than, good arrangement. It seems a very simple proposition to say that all waste-pipes, whose office it is to carry foul liquids out of the house, should be made tight in material and in joint. It is a remarkable fact, however, that leaky joints in soil-pipes and in drains are by no means rare. Probably there are few houses, very few, in which they do not occur. The soil-pipe is put together by inserting the small end of each section into the bell at the top of the section below it, practically like putting the outlet of one funnel into the larger upper portion of another. There may be abundant space for leakage at every joint from the top to the bottom of the house, without there being the least show of the leakage of water. The foul air within the pipe may escape freely through a dozen openings, while the heavier liquid flow takes its easiest and most direct course downward from the point of one pipe through the bell of the one below. When we come to the horizontal run of the soil-pipe in the basement, if an imperfection of the joint occurs on the lower side there is an obvious drip, which continues at least until closed by rust. Similar imperfections in other parts of the joint would not be so manifested. It has recently been demonstrated that there is no safety in the construction of soil-pipes short of that absolute assurance which can be secured only by an efficient test. Plugging all the outlets of the soil-pipe and filling it with water, the slightest leak will be exposed.

However defective may be the condition of an iron soil-pipe, vertical or horizontal, it is perfection itself compared with the usual state of a drain laid under the cellar floor; and here is a point where the least experienced inspector of house drainage cannot be mistaken. Under all circumstances, at least in all work hitherto executed, he should demand as absolutely necessary that the drains under the cellar floor be removed, that the earth which has been fouled by the leakage of its joints and its breaks shall be taken out to the clean untainted soil below, and refilled with well-rammed pure earth or with concrete, the drainage being carried through a properly-jointed iron pipe above the pavement, and preferably with a fall from the ceiling of the cellar to near the floor at the point of outlet—in full sight for the whole distance. It sometimes happens that the necessity for using laundry-tubs or other vessels in the cellar makes the retention of an underground course imperative. When retained, the drain should be of heavy cast iron with most securely leaded joints tested under a head of several feet. When found to be tight and secure, it should not be, as ordinarily recommended, left in an open channel covered with boards or flags and surrounded by a vermin-breeding, unventilated and uninspected space, but closely and completely imbedded in the best hydraulic cement mortar. Its careful testing before this enclosure is of course the only condition under which the work can be permitted.

Tightness of all waste-pipes being secured, the next point in order is their proper ventilation. A good deal has been said, and little has been proved, about the different effects on the human system of the gases of decomposition which have been produced in the absence of a sufficient circulation of air, and those produced where the ventilation and dilution are more complete. The probabilities of the case are, of course, entirely in favor of the latter condition, and it is accepted by all sanitarians as an axiom that all water-ways and all vessels in which organic decomposition, even the decomposition of adhering slime, takes place, should be ventilated as thoroughly as possible. Until about ten years ago nearly all waste-pipes were tightly closed at the top, and were shut from the sewer by a trap at the foot, allowing absolutely no communication between the outer air and the atmosphere of the pipe except as fresh air might be carried in through the water-seals of the traps at each end. At about that time it was becoming the general custom in the better class of work to carry a small vent-pipe, often only one inch in diameter, rarely more than two inches in diameter, through the roof of the house, closing it at the top and perforating it with a few inefficient holes. This had undoubtedly the effect of relieving the pressure on the atmosphere of the pipe caused by the filling of unventilated sewers with tide-water or storm-water, or by a sudden increase of temperature from the admission of hot water. Later, it was accepted as a universal rule, and it became a quite general practice, to carry the soil-pipe above the roof with its full diameter, providing its summit with some form of ventilating cowl. All this constituted not ventilation, but venting. Real ventilation was introduced only with the very recent improvement of admitting fresh air at the foot of the soil-pipe, so as to make a complete circulation from one end to the other—a circulation sufficient to produce, by the diffusion of gases, a very fair ventilation of lateral waste-pipes of moderate length. It is now coming to be understood that ventilating cowls, of whatever form, are an obstruction to the movement of air in the absence of wind, and that, as what is needed is never a vigorous current, but always a living one, these cowls had better be dispensed with. We have learned, too, that the most efficient means for increasing the flow of air through the top is to increase its diameter at the top, enlarging the highest length of a four-inch pipe, for example, to a diameter of six inches. With this arrangement, and with a foot-ventilation four inches in diameter opening at a point where it can never be obstructed by rubbish or by snow, there will be secured a condition perhaps more efficient in improving the condition of an imperfectly drained house than any other one thing that may be done.

I have sketched above, in a very hurried manner, the main outline of a system of house-drainage which may be accepted or which may be recommended by a physician with confidence of securing a good result. To go more into detail in technical matters would be out of place in a paper of this character. Before leaving this subject, however, it is important to call attention to the fact that what is recognized in our houses as sewer gas is in far greater degree the product of decomposition taking place within the house-drains themselves than the product of decomposition in the distant sewer forced into the house through its connecting drain. It is emphatically a case of the beam in our own eye as compared with the mote in the eye of our neighbor. It is a rule which has exceptions, but they are few, that the contained air of the house-pipes is far worse than the contained air of the sewer; and the conviction is growing that the use of a trap to the main drain between the house and the public sewer is more often objectionable than advantageous. Such a trap always tends to check the flow of the drain and to induce deposits whose decomposition is objectionable. Wherever the abandonment of the trap is anything like universal the considerable ventilation of the sewer thereby secured brings its atmosphere to a condition which makes it not objectionable, and generally useful, as a source of movement in the air of the interior drain- and soil-pipe.

(a) Public sewers are more or less good or bad entirely according to their character and condition. As a rule, a well-flushed sewer which is used for no other purpose than the removal of foul waste, built on what is called the separate system, and automatically flushed at least daily, may be considered to be, if well laid and tightly jointed, absolutely safe. A public sewer of large size and of irregular construction, receiving not only household wastes, but the wash of streets as well, may be regarded at least as an object of grave suspicion. These general statements may be so far qualified by the character of the sewers of each class as to run very nearly together; that is to say, separate sewers, with leaky joints, irregular grades, defective alignment, insufficient flushing, and inadequate restriction as to the matters they are to receive, will be an intolerable and dangerous nuisance; on the other hand, a large brick sewer built in the best manner and of the best material, with sufficient fall and sufficient supply to maintain itself in a cleanly condition, is free from the serious drawbacks which usually attach to sewers of this class.

With sewerage as with house-drainage it is not worth while to attempt here to give anything like detailed directions for inspection and for reformation. It will suffice to call attention to this one broad and general rule: Every sewer or drain having for its object the removal of putrescible organic matters must be so arranged as to maintain itself in a condition of practically absolute cleanliness, without, as in the case of storm-water sewers, waiting for the flushing effect of storms, which often come only at long intervals, during which the worst condition of decomposition may be established. Whether the sewer be intended for drainage only or for both drainage- and storm-water, if it contains at any time deposits of any kind, it is defective—more or less so, of course, according to the extent and duration of the accumulation.

Although it should be rigidly insisted upon in every case that the sewer should maintain itself free from deposits, there will still be, unavoidably, a certain amount of foul gas produced by the decomposition of the matters coating its walls, and in order to dilute and to remove this, and perhaps in order to modify their original character, the most thorough ventilation is necessary.

Any sewer or other drain which at any time gives forth the odor of putrid decomposition is in bad condition and should be at once rendered inoffensive. So far as I know, there is no exception to this rule. I have met no conditions in towns of any size where absolute self-cleansing may not be secured. It is worth while, however, to repeat here the statement made above, that sewer gas, in so far as it is a serious factor in connection with the drainage of houses, is the product of the interior pipes of the house much more frequently than of the public sewer in the street.

(b) The disposal of liquid wastes by irrigation, so far as this method is applied to the outflow of public sewers, is not of especial interest here, but an important modification has been made of the system of irrigation which is of the greatest consequence in considering the sanitary improvement of isolated country-houses, of hospitals, prisons, etc., and of houses in towns about which there is a small amount of available land. The process which has been found best suited to the purpose is the invention of the Rev. Henry Moule, the inventor of the earth-closet. He found it a serious drawback to the dry-earth system that it was incapable of taking care of the liquid wastes of the house. He devised a method of conducting the liquid into very shallow drains made with open-jointed agricultural drain-tiles, so porous in their character as to allow the liquid carried by them to escape at the joints into the soil, and thus get the benefit of its purifying qualities without the unsightly and often offensive process of allowing the liquid to flow over the surface. The first use made of this system was about 1866. Since that time its use has extended very considerably both here and in England, and many improvements have been made in its details, so that it may now be accepted as entirely satisfactory.

The process in its best development, as applied to the drainage of single houses, may be thus described, many of the appliances used being the subject of patents: The outflow from the house is delivered into a settling-basin or grease-trap of sufficient size to still the flow, to cause solids to settle to the bottom, and grease and other light matters to float at the top. The outlet from this basin is through a pipe having its inlet at some distance below its overflow-point; that is, at the level of the comparatively clarified liquid, below the grease and above the sediment. The outflow passes into another vessel known as a flush-tank, where it accumulates until it reaches the summit of a self-acting siphon. This height being reached, any considerable addition to the flow sets the siphon in action, and the whole contents of the flush-tank are discharged with rapidity into the drain beyond. The discharge completed, air is automatically admitted to the siphon, and no further flow can take place until the flush-tank has again been filled. The drain, of iron or vitrified pipes tightly joined, is continued to the edge of the ground prepared for purification. It here delivers into a series of open-jointed agricultural tiles, laid with their bottoms not more than ten inches below the surface of the ground. The total length of these tile-drains is regulated according to the discharging capacity of the flush-tank, with a view to their becoming entirely filled at each discharge. Within a short time after the flow has ceased the liquid has all left the pipes and entered the soil, its impurities being retained and its filtered water settling away into the porous or artificially drained ground below. During the interval between the discharges of the flush-tank, a day or more, the process of purification (oxidation) of the retained impurities goes on in the soil, and its thorough aëration prepares it to purify the next discharge. This method of disposal is now employed in connection with hundreds of houses, and its use, which has in some cases continued for a dozen years, is constantly increasing. Its application implies a certain amount of fall, but this amount need not be great. The discharging height of the tank need not be more than twelve inches. The main outlet need not fall more rapidly than at the rate of 1 to 300, and the absorption-drains ought not to fall more rapidly than at the rate of 1 to 600. If the tank can be built on the top of the ground, an average surface fall of 1 to 400 can usually be made to meet all the requirements. Where waste matters are to be removed from cellars and basements below the level of the ground, a greater fall is necessary, or the wastes which are there collected must be thrown to the tank by pumping or otherwise.

Where there is a bit of grass-land a little removed from the house (and from sight), it answers a perfectly satisfactory purpose to dispense with the absorption-drains and to deliver the main outlet directly on to the surface of the ground. The effect in both cases is entirely different from what it would be were the flow of the drains not regulated by the use of the flush-tank. The moment we have a constant slight discharge, either on the surface of the ground or into the absorption-drains, we establish a condition of constant saturation which leads to the over-fouling of a small area, which is rarely if ever purified by aëration. For an intermittent discharge some form of flush-tank is an absolute necessity. It is often found in practice, where the flow from the house is considerable, that the discharge of the house-drains into the settling-basin produces such an agitation of its contents as to set in motion and to carry into the flush-tank bits of paper partly macerated, grease, etc. This has been met by a recent improvement, which consists in building a transverse wall in the settling-basin, which checks the current from the house-drain and causes the flow from the house side of the wall to pass over its top in a thin small current which does not materially agitate the contents of that part of the basin from which the outflow pipe is fed.

(c) The cesspool is still the chief reliance of the world at large. There is nothing to be said in its favor save what may be based on the old adage that "what is out of sight is out of mind." There is everything to be said in its condemnation, whether we regard its contents as a great mass of putrefying and infecting filth, as the source of oozings which travel through crevices of rocks, through layers of gravel, through seams in clay, or through lighter soils into and under cellars and into drinking-water wells and defectively constructed cisterns, or as an ever-active gas-retort supplying the pipes of the house with the foulest products of putrefaction. It is in all respects and under all circumstances a curse, unless placed far away from the possibility of tainting the air we breathe or the soil over which we live, or from which we or others take our drinking-water, and even then it had better be abandoned.

The simple drainage of the soil involves a question of the greatest importance. If the ground under the house or about it is at any time, unless perhaps immediately after heavy rains, saturated with moisture, we have to apprehend a condition of insalubrity more or less serious in proportion to the degree of saturation and the degree of foulness with which this is associated. The drainage requirements of land outside of the house are less easily determined, but it requires nothing more than a casual examination of the cellar in ordinarily wet weather to determine whether or not an improvement of its soil-water drainage is necessary. If it is at such times wet, or even persistently damp, thorough drainage is demanded; and it is only necessary to say that this should be secured by some process which can under no circumstances bring the air of the cellar into communication with the air of a sewer or foul drain.

I have purposely abstained in the foregoing remarks from invading the province of the physician or the physiologist by discussing the influence of bad drainage on the health of those living subject to it. It may safely be assumed that physicians who care enough about the subject to interest themselves in investigating the condition of local or general drainage have convictions concerning it which could not be strengthened by the opinion of one belonging to another profession. The assumption is also confidently made that no intelligent medical man will hesitate for a moment to accept the dictum that the site of the house must be dry, and that it and its neighborhood must be entirely exempt from the influence of foul organic decomposition.