§ 17. A layer of bodies is stated to be about seven years in decaying in the metropolis: to the extent that this is so, the decay must be by the conversion of the remains into a gas, and its escape, as a miasma, of many times the bulk of the body that has disappeared.
§ 18. In some of the populous parishes, where, from the nature of the soil, the decomposition has not been so rapid as the interments, the place of burial has risen in height; and the height of many of them must have greatly increased but for surreptitious modes of diminishing it by removal, which, it must be confessed, has diminished the sanitary evil, though by the creation of another and most serious evil, in the mental pain and apprehensions of the survivors and feelings of abhorrence of the population, caused by the suspicion and knowledge of the disrespect and desecration of the remains of the persons interred.
§ 19. The claims to exemption in favour of burial-grounds which it is stated are not overcrowded would perhaps be most favourably considered by the examination of the practice of interment in the new cemeteries, where the proportion of interments to the space is much less.
§ 20. I have visited and questioned persons connected with several of these cemeteries in town and country, and I have caused the practice of interments in others of them to be examined by more competent persons. The inquiry brought forward instances of the bursting of some leaden coffins and the escape of mephitic vapour in the catacombs; the tapping of others to prevent similar casualties; injuries sustained by grave-diggers from the escapes of miasma on the re-opening of graves, and an instance was stated to me by the architect of one cemetery, of two labourers having been injured, apparently by digging amidst some impure water which drained from some graves. No precedent examination of the evils affecting the public health, that are incident to the practice of interment, appears to have been made, no precedent scientific or impartial investigation appears to have been thought necessary by the joint-stock companies, or by the Committees of the House of Commons, at whose instance privileges were conferred upon the shareholders: no new precautionary measures or improvements, such as are in use abroad, appear consequently to have been introduced in them; the practice of burial has in general been simply removed to better looking, and in general, better situated places. The conclusion, however, from the examination of these places (which will subsequently be reverted to) is, that if most of the cemeteries themselves were in the midst of the population, they would, even in their present state, often contribute to the combination of causes of ill health in the metropolis, and several of the larger towns.
§ 21. It has been considered that all danger from interments in towns would be obviated if no burials were allowed except at a depth of five feet. But bodies buried much deeper are found to decay; and so certain as a body has wasted or disappeared is the fact that a deleterious gas has escaped. In the towns where the grave-yards and streets are paved, the morbific matter must be diffused more widely through the subsoil, and escape with the drainage. If the interments be so deep as to impede escapes at the surface, there is only the greater danger of escape by deep drainage and the pollution of springs.
Dr. Reid detected the escape of deleterious miasma from graves of more than 20 feet deep. He states—
In some churchyards I have noticed the ground to be absolutely saturated with carbonic acid gas, so that whenever a deep grave was dug it was filled in some hours afterwards with such an amount of carbonic acid gas that the workmen could not descend without danger. Deaths have, indeed, occurred occasionally in some churchyards from this cause, and in a series of experiments made in one of the churchyards at Manchester, where deep graves are made, each capable of receiving from 20 to 30 bodies, I found in general that a grave covered on the top at night was more or less loaded with carbonic acid in the morning, and that it was essential, accordingly, to ventilate these grave-pits before it was safe to descend.
This I effected on some occasions by means of a small chauffer placed at the top, and at one end of the grave a tube or hose being let down from it to the bottom of the grave. The fire was sustained by the admission of a small portion of fresh air at the top, and the air from the bottom of the grave was gradually removed as the upper stratum was heated by the fire around which it was conveyed; and when it had been once emptied in this manner a small fire was found sufficient to sustain a perpetual renewal of air, and prevent the men at work in the grave-pits from being subject to the extreme oppression to which they are otherwise liable, even when there may be no immediate danger. A mechanical power might be used for the same purpose; and chemical agents, as a quantity of newly slaked lime, are frequently employed, as they absorb the carbonic acid. From different circumstances that have since occurred, it appears to me probable that numerous examples of strata or superficial soil containing carbonic acid may be more frequently met with than is generally suspected, and that while in churchyards the presence of large quantities of carbonic acid may be frequently anticipated, its presence must not always be attributed solely to the result of the decomposition of the human body.
The amount of carbonic acid that collects within a given time in a deep grave-pit intended to receive 20 or 30 bodies, is much influenced by the nature of the ground in which it is dug. In the case referred to, the porous texture of the earth allowed a comparatively free aerial communication below the surface of the ground throughout its whole extent. It was, in reality, loaded with carbonic acid in the same manner as other places are loaded with water; it was only necessary to sink a pit, and a well of carbonic acid was formed, into which a constant stream of the same gas continued perpetually to filter from the adjacent earth, according to the extent to which it was removed. From whatever source, however, the carbonic acid may arise, it is not the less prone to mingle with the surrounding air, and where the level of the floor of the church is below the level of the churchyard, there the carbonic acid is prone to accumulate, as, though it may be ultimately dispersed by diffusion, it may be considered as flowing in the same manner in the first instance as water, where the quantity is considerable.
Again, where the drainage of the district in which the church may be placed is of an inferior description, and liable to be impeded periodically by the state of the tide, as in the vicinity of the Houses of Parliament, where all the drains are closed at high water, the atmosphere is frequently of the most inferior quality. I am fully satisfied, for instance, not only from my own observation, but from different statements that have reached me, and also from the observations of parties who have repeatedly examined the subject at my request, that the state of the burying-ground around St. Margaret’s church is prejudicial to the air supplied at the Houses of Parliament, and also to the whole neighbourhood. One of them, indeed, stated to me lately that he had avoided the churchyard for the last six months, in consequence of the effects he experienced the last time he visited it. These offensive emanations have been noticed at all hours of the night and morning; and even during the day the smell of the churchyard has been considered to have reached the vaults in the House of Commons, and traced to sewers in its immediate vicinity. When the barometer is low, the surface of the ground slightly moist, the tide full, and the temperature considerable—all which circumstances tend to favour the evolution of effluvia both from the grave-pits and the drains—the most injurious influence upon the air is observed. In some places not far from this churchyard fresh meat is frequently tainted in a single night, on the ground-floor, in situations where at a higher level it may be kept without injury for a much longer period. In some cases, in private houses as well as at the Houses of Parliament, I have had to make use of ventilating shafts, or of preparations of chlorine, to neutralize the offensive and deleterious effects which the exhalations produced, while, on other occasions, their injurious influence has been abundantly manifested by the change induced in individuals subjected to their influence on removing to another atmosphere. No grievance, perhaps, entails greater physical evils upon any district than the conjoined influence of bad drainage and crowded churchyards; and until the drainage of air from drains shall be secured by the process adverted to in another part of this work, or some equivalent measures, they cannot be regarded as free from a very important defect.