The ultimate manurial value of urine is doubtless very great, although when pure or nearly pure it is very deadly to herbage. The only satisfactory way of using urine as a manure is to imitate the farmer, by mixing it with an absorbent material, such as straw, sawdust, peat, earth, paper, cotton waste, wool waste, &c., placing it upon the surface of the ground and digging or ploughing it in.
The best evidence that the humus is alive is the fact that it breathes. The fungi which are destitute of chlorophyll absorb oxygen and give off carbonic acid, in this respect resembling animals and differing from the chlorophyll-bearing plants. The most easily obtained evidence of this is the fact that decaying refuse generates heat, a fact which is easily ascertained by using a thermometer. Thus I have at present in the garden of my cottage in the Thames Valley a heap of privet leaves intermixed with a quantity of fine twigs which give it great porosity and serve to admit a large quantity of air. On the morning of October 21 the temperature of the air was 39° F., and the temperature of the heap of leaves was 57° (18° more than the air). On October 22 there was a heavy cold rain with a cold easterly wind. On the morning of October 23 the temperature of the air was 40° and the temperature of the heap of leaves was 56°. On the night of October 23-24 there was (for the time of year) a very severe frost. My heap of leaves on the morning of the 24th was solidified on the surface by the frost, but the temperature of the interior was 53° while that of the air was 30° (an increase of 23° over the air). This heap, it should be stated, is only a small heap, and would all go into a big wheelbarrow. On the morning of October 24, after taking the temperature of this heap, I turned it over with a fork, putting the frozen top in the centre and altering the position of the constituents of the heap. A quarter of an hour later the temperature of the heap was found to be 32°, and at seven in the evening it was still at freezing-point, or only just above it. The night of October 24-25 was again very frosty, as many as 12° of frost having been registered at a house close by. At eight in the morning of the 25th, however, my heap of leaves showed a temperature of 40°, having risen 8° during this very cold night, and being 20° above the minimum cold recorded in the night. At 7 P.M. on the 25th the temperature of the heap was 42°, and the next morning, after a third very cold and frosty night, it had risen to 45°. The rise of temperature here was clearly due to the respiration of living things, and could not have been in any degree caused by absorption of sun heat. (Since the above was written autumn has come upon us, and the fallen leaves have been collected into a big heap. On November 15 the temperature of this heap was found to be 62° F., and a week later (November 22) had risen to 104° F.!) The fact that the humification of organic matter generates heat is a fact which is of enormous practical value to the gardener and farmer. The market gardens round London, which produce astounding crops and assimilate an enormous quantity of dung, are in a sense extended and mild hotbeds. One hopes that those who are advocating the burning of organic refuse will pause to think, however necessary such a process may be under certain circumstances, how great is the dispersion of energy which such a process involves and how much heat is lost which might otherwise be used for the stimulation of germination and growth in seeds and plants. One hopes also that those who would condemn as foul the humus which contains a large amount of carbonic acid will remember that this gas may only be an evidence of perfectly healthy and vigorous action. The important fact that the tillers of the soil are the most long-lived of all the laboring classes is one which must never be lost sight of.
That the humus breathes and generates an enormous quantity of carbonic acid precisely as an animal does is a fact which the agriculturist must ever bear in mind. Many of the operations of the farm have for their object the loosening of the soil and the admission of air to enable the respiratory processes to go on. Every farmer will tell you that the earlier he can get upon the ground to hoe his turnips the better will be the crop (other things being equal), and every farmer knows the advantage of thorough tillage. If the respiration of the humus is an important fact, it becomes very important indeed not to drown it. It stands drowning no better than a man does, but, like a man, it requires a requisite amount, but not too much, to drink. There can be no doubt that the failure, which is almost general, of so-called sewage farming arises through the drowning of the humus; and it must be borne in mind that sewage water consists to a very considerable extent of water which has been boiled, or is hard, deep well water, and has not the valuable quality of rain-water of containing some 2·5 volumes per cent. of atmospheric air dissolved in it. There can be little doubt that the great trouble to the sewage farmer is the excess of water which drowns the humus. When three or four ounces of excrement are mixed with 1,200 times their weight of water they run small chance of humification, and one must fear that the difficulties of the sewage farmer (financial or agricultural, or both) must increase with the magnificence and extravagance of the water-supply of the town the sanitary interests of which the sewage farm is intended to subserve. The evil effects of too much water have come before me lately in two very striking examples. While going over the experimental farm belonging to Mr. H. C. Stephens, M.P., at Cholderton, on Salisbury Plain, this autumn (which I did in company with a large number of practical agriculturists), there were here and there noticeable in the middle of fields having a uniform quality of soil, and which had been treated in identical fashions, certain large patches over which the growth of turnips, as compared with the rest of the fields was very defective. The explanation offered was that on these patches the animals had been folded in wet weather, that the dung had been trodden into the ground, and the soil had been hardened and consolidated by the trampling of the beasts. Under such conditions (air not being adequately admitted to the pores of the soil) the humification of the dung had been hindered and the crops stunted in consequence. This was a fact new to me, who am only an amateur agriculturist; but I may state that it was unanimously and unreservedly accepted as an adequate explanation by all the farmers present, who seemed to be perfectly familiar with the consequences of folding cattle in the wet. On the other hand, the most fertile patch of the whole farm was where the cattle had been folded for a fortnight continuously on the same spot during the severe frost of last winter, and had been fed upon food which was necessarily brought to them on that spot. The ground being as hard as iron could not be more consolidated by trampling, and with the advent of the thaw there was a general disruption of soil and dung, and humification went on rapidly in earth of which the pores had been opened by the beneficent effects of a deep frost, and which had received an amount of dung which was exceptionally great.
Another experience was a visit to a sewage farm belonging to a town in which brewing is the staple industry. This farm was large (nearly twice as big as at one time was considered necessary) and was composed of a very porous, gravelly soil in a high situation. The manager was an able man, and one felt that if success was to be obtained it was here. But the amount of water pumped on to this ground was exceptionally great, amounting at times to as much as 150 gallons per head of population per diem. The result can be imagined. The humus was drowned, and large tracts of the farm were as wet as a marsh, bore no crops, and never could be made to bear any under such conditions. As soon as it had been saturated it was ploughed up and saturated again, there being no time (let alone other considerations) to grow crops in face of the huge volumes of water which had to be dealt with. Those parts of the farm which were under cultivation grew enormous quantities of water-grass, a noxious weed, and altogether the agricultural aspects of this estate were as gloomy as could well be. As for the effluent, it was thick and turbid, and stunk like a dirty brewery. It was impossible to believe that the effluent had been rendered safe for discharge into a river, and its cost must have approached that of the beer which was sold in the adjoining town. The amount of water seemed to be the trouble here, and clearly the first duty of the municipality would be to divert directly into the river all the storm water and all the water which was used in enormous quantities for refrigerating purposes, and which, being perfectly wholesome, might go into the stream direct. A visit to the pumping-station of this municipality was most unpleasant for the nostrils, and left upon me the impression that the Local Government Board would do well to insist that all sewage committees should have a board-room at the pumping-station and another at the farm, and should be allowed to deliberate in no other place. The humification of excrement in the presence of such an overpowering amount of water is impossible, and I believe that municipalities which are now busy diverting storm water will have to go further and deal with excreta, domestic slop-water, and manufacturers' effluents on different and separate systems. I confess I should like to see water-closets dealt with on an independent system by a vacuum principle such as is advocated by Shone and Liernur. Manufacturers' refuse, which is liable to contain chemicals and antiseptics, is so likely to kill the humus by poison as well as by drowning that it seems impossible to deal with it on any one system, and it is to be hoped that with the advance of chemistry it may be increasingly possible to turn manufacturing effluents to profitable account.
It is now more than ten years ago since I first deliberately drew attention to the shortcomings of modern sanitary methods, and pointed out that the safe disposal of organic refuse was a question of which the biologist, rather than the engineer or chemist, would give us the solution. It is a hopeful sign of the times that engineers are now recognising this fact, thanks mainly to the teaching of the Board of Health in Massachusetts. The purification of sewage is wrought by the presence of living organisms on the filters; and for the due filtration of drinking-water it is now admitted that the filtering material must have a coating of living slime. These are facts which are now all but universally admitted.
Our go-ahead municipalities, formed on democratic lines, are more ostentatious than the worst of Roman emperors. The London County Council wished at one time to give 750,000l. for a site for its house! The central ideas of modern municipalism are the raising of loans and the sweating of the ratepayer. It must be remembered that there is no relation between magnificence and real efficiency. For example, in a town which I sometimes visit I am always interested by a stately pageant consisting of a huge conveyance weighing at least half a ton and looking like a cross between a railway truck and a hearse. This is drawn by a horse weighing 15 or 16 cwt., and this horse is guarded by two men weighing, perhaps, 12 st. apiece. Inside the hearse are eighteen huge pails weighing 40 lb. each, and inside the pails are the weekly excreta of ninety people, which should, if properly managed, certainly not weigh more than 200 lb. or 300 lb. In short, there are about 30 cwt. of gear for the removal of at most 3 cwt. of material. This cumbrous array works, it need hardly be said, at a funereal pace, and there can be no doubt that a lad with a hand-truck coming every day would do the work far more rapidly, efficiently, and cheaply.
It must be borne in mind that the fertility of the soil should bear a certain proportion to the density of population, and that the ability of land to support its population ought steadily to increase, especially if the population enjoys the blessings of free trade. I may perhaps best illustrate my meaning by referring again to the visit which I paid to the farm of Mr. H. C. Stephens, M.P. The down lands which comprise this district consist of a very few inches of humus overlying chalk, the herbage is scanty, and the population of animals (in relation to acreage) necessarily very small. One of the difficulties which the farmer has had to encounter in this district is the obtaining of sufficient water for his stock, and perhaps the most important work which Mr. Stephens has done is to sink a deep well in the chalk. This well, worked by a wind engine and provided with storage reservoirs, gives a supply of water which may be regarded as unlimited. With good water-supply, ample area, and the possibility of importing food which the neighbouring railway affords, it became possible to maintain a very large number of sheep, oxen, and horses for farm and breeding purposes. The animals are all folded, and the whole of their dung is returned to the soil, and the effect produced by this large addition of organic matter cannot fail to strike the visitor, who finds in spots where the herbage was previously so thin as to approach barrenness that he now has to wade knee-deep through a thick felt of grass. All over the farm the effect of adding this organic matter to the soil is everywhere apparent, and it is certain that the need of imported food-stuffs for the animals must diminish in proportion to the increase of fertility of the farm. This estate on Salisbury Plain realises, in fact, the utopia of which I have spoken in 'Rural Hygiene'[9]—i.e., a place where there are water-pipes but no sewer pipes. The indispensable water has by skilful but comparatively simple engineering been brought within easy reach of the human and animal population, but the organic excrements and other refuse, instead of being washed away into a neighbouring valley to poison the inhabitants there, are retained upon the soil to provide extra herbage, extra meat, extra work, and extra wages, with increased contentment and no loss of health. The increased fertility of the soil must have the effect of counteracting poverty and diminishing that charge upon the land known as the Poor-rate, and as for sanitary rates, the very essence of the progress I have been describing consists in the fact that there are none to pay. When the members of the local council in this utopia have mended the roads and paid for the school they may return with a clear conscience to their own business, instead of meddling with that of other people.
The fact that the potential increase of the fertility of the soil is to a certain extent proportioned to the increase of population is a political and economical fact of fundamental importance. The fertility of the soil of a country which imports millions of tons of food ought steadily to increase, and I believe that but for counteracting circumstances free trade ought to have benefited the farmer equally with all other classes of the community. If the enormous quantity of excremental and refuse matters due to free trade had been placed upon the land to increase the national stock of humus the fertility of the soil must have increased proportionately, and the fall in prices due to the competition of imported food would have been proportionately counteracted. If on the farm at Cholderton which I have been describing the well water had been used for washing all the excrement of the animals into the nearest river there could have been no increase of fertility of the soil, and the animals must have been dependent upon imported cake and other food-stuffs to a degree which would never vary, instead of, as at present, tending steadily to get less. Among the nostrums which have been suggested for the relief of agricultural distress are 'light railways,' but as imports and exports are apt to balance themselves, one would fear that the light railway, for every truss of hay or sack of corn which it conveys to the nearest junction, will bring back a frozen carcase of meat or its equivalent. If, however, these light railways (and the existing railways) can bring the refuse of the towns on to the land to increase the agricultural capital in the form of humus, the farmers will certainly have more to sell and our need of imported food (per head of population) will tend steadily to get less. Until—if I may use the expression—we make some serious effort to leave our imported 'cake' upon the land in a form in which it can be advantageously utilised, our needs for importation will never get less, and our state of scare as to the sufficiency of our Navy will get steadily worse as the population increases. It is very bad policy for railways to charge exorbitant rates for the conveyance of dung, because the less dung they import the less will be the export of produce on the return journey. It is impossible to doubt that the man who increases the fertility of the soil of a country deserves well of that country and should be encouraged by the State and his fellow-countrymen. Professor Otis Mason of Washington has gone so far as to say: 'The form of law which does not decrease the amount of taxation proportionally to the yield per acre is not in the line of progress.' And again: 'Any law which punishes a man with taxation for preventing waste, recuperating worn acres, or developing the latent resources of nature, is wicked.' There can be no doubt that taxation presses very hardly upon agriculturists, especially those whose land happens to be within the boundary of a 'progressive' corporation. I have mentioned (p. [149]) a friend who farms 200 acres of land (of which fifteen are grass) in the Thames Valley who pays more than 300l. a year in imperial and local taxes. This is due to the fact that he is under the heel of a 'progressive' board, which, finding it can borrow money at 3 per cent., is making full use of its powers and is fast converting a pretty village into something scarcely distinguishable from Houndsditch.
We may now profitably turn to the consideration of Malaria, a disease which is undoubtedly connected with the soil and which has its habitat in the soil of certain places. Malaria requires for its development decaying organic matter, a high or moderately high temperature, and usually an excess of moisture. Tropical marshes are the elected seats of malaria, but not the exclusive seats, for it is known that certain rocks and arid plains, as well as the sandy estuaries of rivers, are liable to be malarious. The one thing which all, or almost all, malarious districts have in common is the fact that they are barren, or nearly so, uncultivated, and in many cases uncultivable. Malaria is rare in England, but once it was common, and we must not forget that James I. and Cromwell are both of them said to have been victims of this disease, which was rife in London in their time, especially in the Essex marshes and on the south side of the Thames, in Lambeth Marsh and the adjoining districts. An undrained country is uncultivable, and it has been found that drainage followed by cultivation has in this country enormously lessened the amount of malarious disease. Cultivation of land finishes the work begun by artificial drainage. The soil is dried and aërated by tillage, and the organic matter, when the humus is no longer drowned, is oxidised, and goes to nourish plants and trees, which effect an upward drainage no less important than the downward drainage, while the oxygen exhaled by the green leaves cannot but benefit the air of the locality. If we wish to keep clear of malaria in this country we must till the soil and so nourish the humus that its produce may be sufficiently valuable to bear the expense of any artificial drainage which it may be necessary to maintain. If the land of this country goes out of cultivation, as in places it seems to be doing, I see no reason why we or our successors should not witness a recrudescence of malarious disease in localities which are prone to develop it.
It will not be unprofitable in this connection to consider the history of the Roman Campagna. It is generally admitted that the Roman Campagna was not always the desolate waste which it ultimately became. It was prone to malaria, doubtless, but this was kept in check by the large farming population. It is not conceivable that in days when locomotion was slow a city could have attained the proportions and importance of Rome if it had been situated in the middle of a sterile and malarious plain. The neglect of agriculture began in the Augustan age, when Rome was at the zenith of her power, and it is worthy of note that Mæcenas is credited with having incited Virgil to write the 'Georgics' in order to direct, by this fascinating method, the attention of the Roman people to the neglected joys of agriculture. With the acquisition of fertile districts in Africa and elsewhere, not only did the need for home-grown commodities decrease, but it is probable that the profits of home farming decreased also. Corn was imported in enormous quantities, while the expenses connected with the defence of the Empire led to such a merciless taxation of the landholder that in self-defence he was obliged to allow his land to go out of cultivation, and thus escape from the brutal exactions of the tax-gatherer. According to Gibbon, within sixty years of the death of Constantine 320,000 acres of the district of Campania had become barren. Further, there can be no doubt that the Cloaca Maxima and other cloacæ sent to the Tiber much, if not all, of the organic refuse which should have been returned to the land. Finally, there can be little doubt that the extravagant water supply of ancient Rome must have had the effect of causing neglect of local wells, and as the water of the aqueducts was supplied to places in the Campagna as well as to Rome itself, the discontinuance of pumping must have helped to leave moisture in the soil at the same time that an extra supply from a distance was giving an additional quantity to it. As these great works of engineering did away with the necessity of manual labour, and as the barren land stood in no need of husbandmen, it is not to be wondered at that the problem of the unemployed grew urgent in Rome. We hear that in the later days of the Empire the masses congregated at the baths or waited whole days at the doors of the amphitheatre while they were fed with doles of bread or corn supplied from the public granaries. With a dense idle population and with barren and unwholesome surroundings the amenities of Rome as an imperial residence declined, and on this account it was probably that Diocletian seldom visited it; and one cannot but think that the social and sanitary conditions of the capital were among the causes which led Constantine to abandon it in favour of his new city on the Bosphorus. Finally, one is not surprised to hear that when Alaric took the city in the beginning of the fifth century he did so, not by direct assault, but by seizing the huge granaries and magazines at the Port of Ostia, and then offering to the unhappy Romans the choice of surrender or starvation. We are often asked to admire the Roman aqueducts, and Rome is not infrequently held up to us as a model to be copied. I fear we are copying her only too exactly, and I fear that equally with Rome we shall find out the futility of a brutal and reckless expenditure mainly directed towards the starvation of the soil and a senseless struggle with conditions imposed on us by Nature. I have heard it suggested that the cultivation of the soil of England is of no importance, that our islands are destined for residential and manufacturing purposes only, and that our sustenance is to depend entirely upon 'big-bellied argosies' bearing all the treasures of more fertile climes. But the cultivation of the soil and the nurturing of the humus have important bearings upon questions other than food supply, and if we continue to starve the humus and to convey our filth beneath it instead of upon it, I fear that the cost of living in this country is likely to increase, while the pleasures of existence will diminish.