It is often stated that to deal with excremental matters separately from the slop-water is no advantage either from a pecuniary or sanitary point of view, because:

• 1. Slop-water is as foul as sewage composed of excrement and slops.
• 2. A system of sewers is necessary for the slop-water, and it is not easier to treat slop-water alone than it is to treat a mixture of slops and excrement.

The following tables, from the 'Report of the Royal Commission on Rivers Pollution in 1868,' are given by most sanitarians to show that the difference in degrees of impurity between a water-closeted town and a non-water-closeted town is very slight.

Average Composition of Sewage

In Parts per 100,000

This table being not unfrequently quoted in support of the contention that slops alone = slops + excrement, I may be excused if I examine it somewhat critically.

I will take the table in grains per gallon and simplify it somewhat.

We shall all of us be ready to grant that the addition of excremental matters must be something extra added to the sewage, and that such extra matter must be either in suspension or solution. The fact, therefore, that the total solid and suspended matters is less by 3½ grains in the water-closet towns than in the midden towns can only be accounted for by the enormous dilutions of the excremental matters in the sewage. Notwithstanding this dilution we find that the water-closet town sewage contains 20 per cent. more combined nitrogen than midden town sewage, 23 per cent. more ammonia, and, what is very remarkable, 35 per cent. more suspended mineral matter.

This excess of mineral matter in suspension could only be caused by the precipitation of mineral matters by the ammonia and sulphuretted hydrogen formed by decomposition of the albuminous and other organic matter. This excess of mineral matter in suspension must therefore be taken as a measure of the enormously increased putrefaction in water-closet sewage, a putrefaction probably to a great extent brought about by the millions of microbes which are provided from the human intestines with the excrement, and we must therefore assume that the increase of mineral matter in suspension is an indication that a large quantity of foul putrefactive gases has been given off into the streets and houses of water-closet towns.

This table, therefore, seems to me to conclusively demonstrate that the sewage of water-closet towns is far more bulky and far more filthy and dangerous than the sewage of midden towns.

Sewage is not to be regarded too absolutely from its chemical side. We must use our senses, inclusive of our common sense, in coming to a conclusion, and we must not pin our faith on analyses alone. When I am told that it is of little use to deal with solid excreta, because the liquid household slops alone are as foul and difficult to treat as the complete mixture, I confess I am incredulous.

When I see the housemaid's pail filled with three gallons of soapy water and perhaps a pint of urine, am I to believe that the addition thereto of five ounces of solid excrement, a second half pint of urine, and a square foot of paper, will make no difference to its foulness and cause no increase of difficulty in its purification? Credat JudÆus Apella! Such a statement is manifestly absurd.

Again, we must remember that it is the solid excreta which constitute not only the foulest but the most dangerous ingredient of sewage, the only one which has caused widespread epidemics again and again, the one which has hung a load of debt round the neck of every municipality in the country.

The other ingredients of household slops, unlike the fÆces, are little liable to contain pathogenic microbes. The urine of a healthy man is, as we all know, sterile when passed. In diseased conditions it may occasionally possess infective power, but this is a speculation rather than a practical fact acknowledged by the sanitarian. A large proportion of cooking-water has been boiled, and is therefore sterile, and the same may be said of the water in which our linen has been washed. Household slops, therefore, are not liable to be really infective.

They are nitrogenous, and consequently, if allowed to stagnate by mismanagement, they become very foul from decomposition, but that they are capable of producing epidemics has not yet been proved. Between excrement and slop-water there is this difference, that solid excreta are foul-smelling ab initio, but slop-water (if we except the smell of water in which cabbage has been boiled) only becomes foul if it is mismanaged.

In places which are not overcrowded a great deal has been done when the wholesome treatment of the solid excreta has been arranged for, and I feel that to neglect the doctrine that 'half a loaf is better than no bread,' and to discourage people from dealing with solid excreta, because they do not see their way quite clearly for the disposal of slops, is most dangerous.

One thing is certain, viz., that if the solid excreta are dealt with by dry methods the liquid sewage will be 25 per cent. less bulky than otherwise would be the case.

I feel sure that if, in our anxiety to prevent the pollution of rivers, we fail to appreciate the biological differences between excrement and slop-water we shall make a mistake, which in the end will be no real advantage to the streams. If, therefore, villages and places where the population is sparse make serious efforts to deal with excreta, they should have at least some breathing-time allowed before the fish in their streams are deprived of the luxuries which they doubtless obtain from kitchen slops.

When fÆcal matters are mixed with the slops, the mixture is so offensive that we are compelled to place it at once beyond the reach of the nose or eye, and the presence of sticky fÆces and large quantities of paper makes any attempt at filtration practically impossible. Domestic slop-water when fresh is not offensive, and is very rarely dangerous; and by attention to certain details it can be easily dealt with.

Domestic slop-water consists of:

• 1. The waste from kitchen and pantry sinks, which often contains dissolved albuminous matter, food particles, dissolved and suspended fat, a considerable amount of coffee grounds and tea leaves, and sundry odds and ends, the result of house-cleaning, such as fluff, bits of string, little scraps of paper and rags, fibres from brooms and brushes, &c. These materials are very apt to accumulate, and to block drains; and if this form of slop-water is to be effectually dealt with, it is essential that the suspended matter be strained out. The purposes which the kitchen and pantry sinks subserve require, according to Notter and Firth, about 3·75 gallons of water per head per diem; and allowing for evaporation, the slop-water must be less in quantity, so that if we say that these slops average 24 gallons per diem for a household of 7 persons, we shall be not far from right.
• 2. Bedroom slops, consisting of soapy water and urine. Allowing for a daily sponge bath, these amount to about five gallons per head per diem, or thirty-five gallons for a household of seven persons. The suspended matters in these slops (soapsuds chiefly) are in such a fine state of division that they easily filter. They may contain waste matches, a few hairs, a small amount of fluff from towels, and an occasional bit of paper.
• 3. The water from fixed baths amounts to about thirty gallons per bath per diem, and in a household of seven would not probably amount to more than sixty gallons a day. It is so clean that it ought not to occasion any trouble.

Assuming the clothes-washing is not done at home we should have fifty-nine gallons per household of seven per diem without fixed baths, and 119 gallons with fixed baths; and if the washing be done at home, then three gallons per head per diem must be added, or twenty-one gallons for a household of seven, giving a maximum of 140 gallons per diem for a household of seven.

Fifty-nine gallons per diem would put upon an acre of land the equivalent of an inch of rain (22,624 gallons) in 384 days, and the equivalent of an inch of rain on a quarter of an acre in 96 days.

One hundred and forty gallons per diem would be the equivalent of an extra inch of rain on an acre in 162 days.

These amounts are trivial, and if the water be supplied from a private well in the grounds it is evident that, allowing for evaporation, we should pump from the subsoil rather more than we return to the surface. Again, it must be remembered that the house with the greatest amount of slops has, as a rule, the largest curtilage. A mansion containing twenty persons with unlimited baths, laundry, and stables would not probably give more than 40 gallons per head, or 800 gallons a day, which is a trivial amount when considered in connection with a park of 20 or perhaps 200 and more acres.

It is necessary to insist that the amount of slop-water to be dealt with in isolated houses is usually trivial in proportion to the land available for its purification. Tidy was of opinion that, employing intermittent downward filtration for the purification of previously precipitated crude sewage, an acre might be sufficient for 7,000 persons. This would give 1/1000 acre, or about 44 square feet, for a household of seven. At this rate my consulting room in London, which measures 24 × 18 = 432 square feet, would be an area large enough for nearly 70 persons. I think the estimate is too small; but even if one multiplies it by ten it is evident that the amount of land necessary for treating the domestic slop-water of a house is much smaller than might be supposed.

In places where unlimited water is obtained by merely turning a tap these estimates are very liable to be exceeded, especially when those who turn a tap on are too forgetful or lazy to turn it off.

I feel certain that anyone who experiments on this matter as I have done will be simply astounded at the small amount of ground which is necessary.

Critics of the plans which I have advocated, and am now about to advocate, sometimes hint that the whole curtilage of one's house must be unwholesomely sloppy.

Such a statement shows a complete ignorance of the whole subject.

Few, if any, of the writers of hygienic text-books seem to have really studied the life-history of slop-water, and it is matter for regret that in some of these books the chapters devoted to domestic hygiene deal more with patents than with principles, and are illustrated more by woodcuts culled from tradesmen's catalogues than by any practical knowledge possessed by the writer.

Principles of Slop-Drainage

If domestic slop water is to be dealt with successfully it is necessary—

1. That all waste pipes terminate well above the level of the ground.

This is a point too much neglected by architects, who are very prone to carefully put all waste pipes below ground level, so that any purification of slops without pumping is impossible.

Allowing a fall of, say, 1 in 10, it is evident that for every foot above ground at which a waste pipe terminates it is possible to deliver the waste on to the surface of the ground at 10 feet from the house. Thus the bedroom sink waste at a height of 10 feet above ground level might be made, if so desired, to deliver its waste 100 feet from the house. It is often necessary to take the waste pipes from the first floor over the path surrounding the house. This is easily accomplished without causing any unsightliness by placing an arch over the path. Such arches may be of galvanised iron for a cottage, or of masonry for a mansion, and are soon hidden by creepers.

Figs. 24 and 25 illustrate how this principle may be carried out; in the one case by a rustic arch costing a few shillings, and in the other case by a porch and arcading of a more ambitious description. Fig. 24 is from a photograph of an arch in actual use. Fig. 25 has been furnished by Mr. Cutler.

When pipes are provided with a rapid fall there is little tendency for water to freeze in them, but in severe climates it might be necessary to pack the pipes.

The waste pipes of kitchen and pantry sinks are, in London, almost always below ground level, it being the custom to place the kitchen and offices in an underground basement; and I have known London architects who have provided country houses with similar abominations, so that the sewage of a basement has to be lifted before it can be properly treated. If this evil is to be avoided, it is essential that the waste pipes of kitchen and pantry sinks terminate at least two feet above ground level. This is a minimum, and if a greater fall can be obtained, so much the better. Kitchen and pantry waste is full of dissolved and suspended matter, and a careless cook will throw down the sink enough food to keep a pig or a dozen fowls. This waste is very prone to become offensive, and it is advisable that it be thoroughly strained before flowing away. Not only should the waste pipe have a fixed and immovable strainer below the plug, but a sink basket should be used, and the waste should be still further strained in a manner to be presently described.

Experimenting upon this point, I have found that stagnant slops become, as a rule, offensive within 24 hours, even when exposed to the air. Thus I tried the experiment of filtering bedroom slops through a trough filled with stones and provided in the middle of its length with a diaphragm reaching from the top to within an inch of the bottom, and having the outlet only an inch or so below the level of the inlet. This caused stagnation and great foulness, which disappeared immediately the outlet was placed at the lowest level, and stagnation became impossible. Soapy water mixed with urine soon becomes foul if allowed to stagnate in traps, but it has never in my experience been foul if poured upon the earth and allowed to soak away. With a good fall and with the outlets of pipes freely exposed to the air, traps are not necessary, and as all forms of traps are but miniature cesspools, this is a great gain. A trap is never possible in an outside metal pipe because of the fear of frost. The abolition of traps is not only necessary, but a very great gain indeed.

This may be effected by means of

Filtration Gutters

The gutters which I have used, and which have been found to answer in a manner which has far exceeded my expectations, are constructed as follows:—

A trench 2 feet deep and 18 inches wide, and of a length varying with the circumstances, is dug, and filled up with porous material, such as builders' rubbish, old crockery, and tins, stones, &c., &c., to within a few inches of the surface, and upon this rubbish, previously rammed, walls of concrete or honeycomb brickwork are formed, provided with a ledge sufficiently wide to support a perforated tile, the perforations being big enough to admit a large sized knitting-needle, say ? in. in diameter. The porous rubbish reaches to within an inch of the under surface of the tile, and the sides are planted. The gutter may, if necessary, be protected by a grating.

Or the gutter may with great advantage be placed upon a bank with gradually sloping sides.

In both cases the sides of the gutter should be planted with quick-growing shrubs, and it will soon become ornamental. Such a slop-gutter on a raised and planted bank would form a most excellent boundary fence. These gutters are shown in figs. 26 and 27. The perforated tile which forms the floor of this gutter is a most important part of it, because it allows the gutter to be cleared of dead leaves and other rubbish, which inevitably fall into it, and it protects the porous material from getting clogged. It breaks the force of the water and prevents the downpour from the pipes from ploughing up the rubble, which is a most important matter. I have used various things for forming the floors of these gutters, and have found nothing better than the perforated tiles which are used for forming the floors of malt kilns. I have no doubt that the gutter could be made perfectly well in galvanised iron. What lengths of such gutters should be provided? To answer this question I can only give my own experiences.

Two years ago I constructed such a gutter for a girls' school where there are between 30 and 40 day scholars and boarders. I dug out my trench leading into a natural rivulet, and I formed a gutter 40 feet long. I do not think the slops in this case have ever travelled as much as six feet, and there is no evidence that a drop of slop-water has ever touched the rivulet. The privets have grown, but the gutter has never been foul, and when the tiles have been taken up the porous rubbish beneath has been found perfectly sweet, and there has been no sloppiness at the sides.

A similar gutter on a bank was provided for a six-roomed house, and the slop-water has never travelled to the end, or anywhere near it, notwithstanding a considerable fall.

The water of a fixed bath has run for nine years into a gutter 20 feet long, and at times as much as 120 gallons a day has flowed into it, but the water is never visible two minutes after the waste has ceased to flow; there has been no foulness of any kind, and the only effect has been to make the shrubs grow.

The bedroom slops of a country mansion with twenty-three inhabitants were taken, eighteen months ago, into a plantation, and the only result has been that the limes have thrown up suckers, but there has been neither sloppiness nor foulness.

The bedroom slops of a cottage with five inhabitants have run for five or six years along a gutter 12 feet long, at the foot of a privet hedge, and there has been neither sloppiness nor foulness, except when, as stated above, I produced stagnation.

The waste of fixed baths is almost clean, containing nothing but a little soap at most; bedroom waste contains soap and urine, but no solid particles of any size to give trouble, except a stray bit of paper, or an old match, or a few hairs, and some fluff from towels, which will all be caught upon the perforated tiles, and can be swept up occasionally.

The waste from kitchen and pantry sinks needs careful straining and filtering before it is allowed to flow into an open gutter. I have mentioned the necessity of providing strainers and a sink-basket, and I now proceed to describe the slop-filter which is advisable for the kitchen sink (fig. 28). The waste-pipe of the sink must terminate 2 feet or 2 feet 6 inches above the ground level, and be provided with a reversible nozzle delivering over a filtering vessel made of concrete or iron. This filter is in duplicate, and is provided with a diaphragm reaching to within an inch of the bottom. Each half of the vessel measures 1 foot by 1 foot 6 inches, and is 2 feet 6 inches deep, and has a capacity of 3·75 cubic feet. The outflow is immediately beneath the diaphragm, and empties into the open gutter. Each half of the filter is filled with stones varying in size from a hazel-nut to a walnut, and the waste is allowed to flow through one half of the filter, and then, when that half gets foul, the nozzle is reversed, and the second half is brought into use, and the half first used can be cleaned out. The filter must be provided with a fine copper strainer, and if the slops be carefully strained the filter will not get foul for months; but if lumps of fat and slabs of cabbage-leaves be allowed to get into the filter, it soon gets foul, as does the abomination known as a fat-trap.

The method of purifying sewage by 'intermittent downward filtration' is well understood, and the methods advocated here are merely modifications of what has been done in this country, and also by the Massachusetts Board of Health.

What is meant by 'intermittent downward filtration'? How frequent are the intermissions?

The intermissions usually recommended are 'sewage for six hours and rest for twenty-four hours,' but my belief is that the purifying action of the filter-bed ceases directly the filter is filled and water-logged. The intermissions must be perpetual. The supply of slop-water in a private house is essentially intermittent, and this perpetual intermission is the secret of the success of the methods I have indicated. Between nine at night and seven in the morning—ten hours out of every twenty-four—the flow of slop-water is usually nil. Between 8 A.M. and 11 A.M. is the time of the bulkiest flow, but even this intermits. A housemaid's pail with its three or four gallons will come once in ten or fifteen minutes, so that the filter is always being emptied, and as the water drains off the fresh air follows it. The water of a fixed bath is practically clean, and gives the filtration gutter a vigorous stir, which does nothing but good. The domestic intermissions are invaluable. When sewage is collected in a tank and is then allowed to flow without intermission for six hours at a stretch, it is doubtful if the greatest purifying power is obtained from the filter.

Rain-Water.

Another point of great importance is the bestowal of rain-water. The usual method is to conduct the rain-water from the eaves by means of pipes which open directly into an underground sewer or empty over a gully which runs into an underground sewer. This underground sewer conducts the rain-water either to a main sewer or cesspool, and the important fact to be borne in mind is that the length of underground pipes, whose main function is to conduct rain-water, are nothing but prolongations of sewers or cesspools which conduct the gases of putrefaction to many points round the dwelling, either at the ground level or the roof level.

There can be no reason why rain-water pipes should not end in a 'shoe,' and discharge over open gutters which might flow to a gully, if absolutely necessary, at a distance from the house. The practice of taking rain-water direct into underground drains is a great cause of damp walls. A year or so ago the rain-water pipes of a country house well known to the author, which ran direct apparently into the underground drain, were examined. In every case the underground drain was broken and leaky, and in some places completely choked by the roots of plants and trees, while the rain-water got away as it could, and kept the foundations of the walls perpetually soaked.

In the London house, with its cave-dwelling basement and narrow area, it is inevitable that the rain-water must flow to an underground sewer more or less directly, but there is no reason why this Cockney necessity should be adopted in the country. It is obviously advisable to conduct rain-water clear of the walls and foundations. The mediÆval gargoyle was useful in this way, and I think I am right in stating that the 'flying buttress' was occasionally made to serve the purpose of a water-gutter with the same object.

Refuse.

It has been said that classification is the basis of all science, and it most certainly is the basis of the scientific disposal of refuse. Refuse matter is most varied in its nature, and the items of which it is composed—excrement, rags, bones, paper, straw, sawdust, and other packing materials, cinders and ashes, old crockery, broken glass, old metal, &c.—all demand a different method of treatment.

When I see the grimy gentlemen in fan-tailed hats engaged in the marvellous operation of climbing over spiked railings with the object of filling a huge lumbering cart with a mixture of some or all of the things mentioned above, I feel that they are occupied in a bit of wilful mischief, and are merely increasing the dangers and difficulties of that sorting which is inevitable. In cities house refuse should be collected every day, and the sorting should be done at once by the collector, with the intelligent co-operation of the householder. Things dissimilar in nature should never be mixed. The first division is into putrescible and non-putrescible, and the former should be sent forthwith to the farmer to be dug into the ground. The non-putrescible refuse—glass, crockery, cinder, ash, metal—if sorted and temporarily stored in bins, would probably pay the cost of its collection and removal, and might perhaps yield a slight return. A great deal of the non-putrescible refuse might be of use to the sanitary authority on the spot for making foundations for paths and roads, or for scattering on the streets in slippery or frosty weather. Ash (not cinder) beneath the gravel on a garden path gives in time a firmness and stability which are remarkable. Whether it would work in with the macadam in road-making, and cause a similar improvement in the road, I do not know. It is difficult to understand why it should not do so. Non-putrescible refuse is not a danger to health, and it is certain that a great deal of it might be used for various purposes by the sanitary authority.

This immediate sorting is only possible when such materials are collected every day and the bulk is small.

It seems to me that much of our municipal scavenging is too magnificent, and that it is often inefficient in proportion to its magnificence. The nimble boys who collect the street droppings and store them in bins which contain nothing but the valuable and marketable manure are the type of what is good. The showy Clydesdale slowly dragging the most lumbering cart conceivable filled with an unmarketable mixture is the type of what is bad.

Farmers are shy of taking London sweepings, because, as one told me, 'they send such stuff.' All organic refuse is good for the land, but the farmer wants it in a form which does not hinder tillage. Pieces of oil-cloth, hamper lids, dead dogs and cats, and old tin canisters, are a nuisance to the farmer, and a very slight admixture of such things spoils the practical value (a different thing to theoretical value) of the manure which is mixed with them.

The sanitarian who loses sight of classification, and who, in his eagerness for a big scheme, is neglectful of details, has not mastered the elements of his trade.

The only rational treatment for excremental matters is immediate superficial burial, with a view to the production of crops, as detailed in 'Rural Hygiene.' It is to be hoped that, with this object in view, some municipality will purchase a tract of land and endeavour to give the poor an object-lesson on the right use of refuse. If convenient access to such a farm by means of canal, river, or railway siding could be obtained, it would make little difference whether it was two or twenty miles from the town, but the nearer the land is to the houses the better. Such a farm must be hand-tilled, and, if skilfully hand-tilled, would certainly produce as much food as a market-garden. It would employ an enormous amount of labour, and would at least pay its labour bill. I am not advocating that such a farm should be used as a playground for the semi-criminal, semi-imbecile, and generally incompetent class who go to form the 'unemployed'; for the trade of agriculture, to be successful, demands both skill and energy. The 'unemployed' should be set to stone-breaking, street sweeping, dung-collecting, road picking and ramming, and scavenging generally, under the eye of foremen in town, and then, if found worthy, they might be exported to the farm.

Figs. 29 and 30 are intended to show the plan and section of a group of the smallest town tenements, with a scavenger's alley between them and the three gutters, two closed at both ends, to be filled with absorbent material to collect the urine, and one to be filled with non-absorbent material to filter and aËrate the slop-water, which should always flow in open channels when practicable. The 'scavenger's alley' should be protected by gates. It is thought that the excrement would be primarily collected in comparatively small vessels, like garden water-tanks upon wheels. The excrement having been allowed to drain before collection, and being in a semi-dry, sticky condition, would have no tendency to slop about during a journey, and in a covered vessel such as I have described might be sent any distance without danger or offence. Arrived at the farm the tank would be transferred to a second pair of wheels, and by being tilted would easily deposit its contents in a furrow previously made in the ground with a spade. The tank should be dried and lime-whitened and returned to the town, and three days after the deposit of the excrement in the ground, plants of the cabbage order should be dibbled in. Cabbages and their allies are the only plants which really flourish in the fresh material; but after the cabbage crop has been harvested any garden crop may be grown, and it will be found that the fertility of ground treated as I have suggested is very great and very persistent.

The best method of treating kitchen waste and putrescible refuse, such as cabbage leaves and the trimmings of vegetables, &c., is to throw all together into a heap enclosed by a circle of wire netting. In the course of a few months complete humification will take place.

---