Popular Science Monthly/Volume 19/September 1881/Are Cemeteries Unhealthy?

Written in response to an ongoing debate whether cremation or burials were better for the public health. First published in French as "Les prétendus dangers des cimetières", Revue Scientifique, 18 June 1881, pp. 779-782.


IF the tomb is characteristic of humanity, as Vico has said, the cemetery, M. Pierre Lafitte remarks, is absolutely necessary to all human society. It not only furnishes a more or less hygienic method of disposing of the bodies of those who are no more—it is also a fundamental institution, in the sense that it is a symbol in no way trary of human continuity. The cemetery ought, therefore, in every city to be preserved and improved, as something indispensable to the intellectual and moral improvement of the people. It constitutes an interest of the first order, the care of which justifies all necessary efforts and expenditures. With a large part of the public, however, hygienic considerations far outweigh all the moral and social advantages to be derived from the maintenance of cemeteries; and, in justice to the views of this class, it is proper to inquire to what extent the existence of cemeteries, in or near a city like Paris, can be dangerous to the public health.

The injurious effects attributable to cemeteries can be exhibited only through the air, the soil, and the waters. Let us examine each of the three cases.

The air may be contaminated by the disengagement of poisonous gases, or by the propagation of miasms.

The decomposition of bodies in the earth is a real organic combination; its products are quite well known. The principal and most abundant of them is carbonic acid, a substance that is generated by the slow combustion of the carbon contained in all organic matter, vegetable or animal, whether it be a blade of grass, a leaf, wood, manure, or a dead body. It may be disengaged from the soil in cemeteries, and most hygienists have till now considered it one of the principal causes of their insalubrity. This is a mistake. We have on a recent special occasion made an approximate calculation of the maximum quantity of carbonic acid that can be produced in the cemeteries of Paris. The results of these calculations, which are based upon numerous weighings of corpses made in several hospitals and on the most authentic data of the chemical composition of the human body, show that this quantity is infinitely less considerable than has been supposed. The total weight of the bodies consigned each year to the cemeteries in Paris is 1,389,000 kilogrammes (3,472,500 pounds). If all their carbon were transformed (which is not the case) and disengaged as carbonic-acid gas, they would furnish 1,257,000 kilogrammes (3,142,500 pounds) of that gas in five years. Now, according to the calculations of M. Boussingault, we may estimate the quantity of carbonic acid produced in Paris, by the respiration of men and animals and the different processes of combustion, at 18,000,000 kilogrammes (or 45,000,000 pounds) in twenty-four hours. The combustion of illuminating gas alone in Paris (218,813,875 cubic metres) produced last year a quantity of carbonic acid thirty-five hundred times more considerable than all the dead buried in the cemeteries during five years could give at the maximum rate of exhalation. The Grand Opera-House alone gives out every year thirteen times more carbonic acid from its gaslights than could be disengaged from all the cemeteries put together, even if all their carbon were converted into gas.

After examining these figures, and comparing them with the very precise experiments recently made by MM. Jules Reiset, Muntz, and Aubin, on the proportion of carbonic acid in the atmosphere, which go to show that the proportion of this gas in the air of Paris is no more considerable than in the country, we have a right to affirm that positively no danger to the public health exists from this source.

The truth is, that most of the accidents which happen in burial-places must be attributed only to confined carbonic acid. These accidents are, moreover, much less numerous than is supposed. Different authors do not report more than twelve or fifteen cases, and the theory that cemeteries are centers of infection has been built upon this small basis. Such accidents have been attributed to "pestilential emanations, to certain subtile and deleterious gases, to unhealthy miasms," etc. In reality, the accidents noted have been caused by the carbonic acid which has settled in the pits or vaults by virtue of its superior specific gravity. The same happens much more frequently than in cemeteries, in lime-kilns, marl-pits, some cellars, fermenting vats, everywhere, in short, that carbonic acid is liable to accumulate within a limited space.

The absence of any facts relative to other gases than carbonic acid that might be disengaged in the course of cadaverous decomposition ought to have made those who are so sure of the dangerous character of cemeteries more circumspect; notwithstanding there are no such facts, these persons, besides magnifying the dangerous consequences of the liberation of carbonic acid, speak also of the no less fearful dangers which result from the generation of "certain gases and of certain volatile products." Only two gases have been found to be present to an appreciable extent in the confined air of mortuary vaults, or in the atmosphere immediately surrounding a body in decomposition—as, for instance, within the inclosure of a leaden coffin. These two gases are poisonous when breathed in a certain quantity; they are ammonia and sulphuretted hydrogen, forming, when they combine, sulphohydrate of ammonia. The most delicate reagents disclose no trace of these gases in the free air, nor even in the atmosphere of the cemeteries of Paris, although such tests often, when applied in the same manner, indicate their presence in water-closets, sinks, cellars, and sewers. In the absence of ammonia and sulphuretted hydrogen, we might (though no one has yet done so) imagine the presence of the ptomaïnes, those alkaloids of dead bodies recently discovered by Professor Selmi. We anticipate this accusation, by observing that the presence of ptomaïnes in the open air has never been detected. It has been proved that they are not always poisonous; and they exist only in inconsiderable quantities. So far as is known, the ptomaïnes may be simply resultants of the transformation of other principles during extraction, for "they sometimes exhale a perfume like that of certain flowers, as the orange or wildrose, and of certain aromas"—odors which it is well known are not found among those of cadaverous putrefaction. Moreover, these alkaloids, according to Selmi, are readily decomposed in contact with the air. The ptomaïnes, then, can not enter into account in establishing a noxious character for cemeteries.

Assuredly there are miasms. We do not mean by this term those famous entities by which populations have been struck with terror, but those infinitely small, inferior organisms, the microbes, whose existence can not be disputed after the brilliant investigations of contemporary micrographs, especially those of M. Pasteur. We have no disposition to ignore the existence of four or five species of microbes, the destructive effects of which appear to be well established, such as the anthrax-bacteria, the septic vibrion, Obermeyer's spirill, the micrococcus of the hen-cholera, and some other less well-known bacteria. But, without denying that the air may convey infectious germs, and that these may penetrate into the human organism through various channels of absorption, facts which have become almost classical, we still have to examine whether cemeteries, more than other places, give rise to these miasms, these legions of microbes, whose presence in considerable numbers in certain places, notably in hospital-wards, is incontestable.

A number of well-established facts go to prove that the different germs are destroyed by the combustion of corpses in the earth as soon as putrid fermentation begins. We cite the characteristic fact of the disappearance of the carbuncular virus in the bodies of animals that have died of the plague-sore, from the moment the body begins to putrefy (Pasteur, Collin), a fact which is practically recognized by all the horse-killers, who are aware that infected subjects shortly after death cease to be dangerous to them. A more important fact is that the very exact micrographic researches undertaken by M. Miquel in the cemeteries of Paris have certainly shown that there do not exist in them any centers specially productive of germs of cryptogams. This learned physician has ascertained, contrary to the opinion of many authors, that the vapor of water which arises from the soil, from rivers, and from masses in active putrefaction, is always micrographically pure—that is, it contains no microbes; that the gases proceeding from buried matters in decomposition are always free from bacteria; that even the impure air which is caused to pass over putrefied meats, instead of being charged with microbes, becomes fully purified, on the single condition that the infectious and putrid filter is in a condition of humidity comparable to that of the ground at about a foot below the surface. Finally, none of the numerous species which M. Miquel has isolated and inoculated upon living animals has shown itself capable of determining pathological troubles worth mentioning. After this, we may with perfect security put aside those pretended miasmatic emanations, those mysterious effluvia with which certain hygienists have gratuitously frightened an inexperienced public, and which some speculators have turned to good account for themselves.

Regarding the extent to which the soil is affected in consequence of burials, we are in possession of exact and well-established facts. The time required for the earth fully to transform organic matter that may be buried in it varies according to the physical and chemical nature of the soil: in some grounds bodies are, we might say, devoured in a few days; more commonly the time required to transform a corpse is estimated at from five years, as in Paris, to twenty years, as at Geneva, and even more in some places. Authors also differ respecting the time needed for the operation: Gmelin and Wildberg believed that it takes thirty years, while Maret thought that three years are enough.

Legislation based on this point has designated a variety of periods after which burial-grounds may be used over again. At Frankfort, thirty years is the standard; at Leipsic, fifteen years; at Milan and Stuttgart, ten years; at Munich, nine years. Generally, the time necessary for a complete destruction of the body is estimated in France at five years, but this limitation is not at all absolute, and in many cases burial-grounds may be used anew before that time. In the majority of the experiments made by them, Orfila and Lesueur found that bodies were reduced to skeletons at the end of fourteen, fifteen, or eighteen months. After that time, the soil under the vivifying influence of oxygen resumed its original qualities.

On this point, we may assert, contrary to certain affirmations, but in accordance with experiments the importance and value of which are guaranteed by the name of the author, M. Schützenberger, that, so far as the cemeteries of Paris are concerned, no saturation of the soil, either with gases or with solids, exists. The recent experiments of this chemist have resulted, in effect, in showing that the soil in the Parisian cemeteries is still in a sufficiently favorable condition as to its composition to effect the absorption of the gases and the complete transformation of the solid and liquid matters resulting from the putrefaction of the bodies that may be buried in them. The analysis, so far as it refers to gases at least, has given identical results with the analyses of good arable lands. Moreover, there is nothing to prevent the modification of the soil of cemeteries by means of suitable applications for augmenting the intensity and rapidity of its combustible force. Such applications are certainly not beyond the means of modern agricultural chemistry.

No important instance of the contamination of waters has been established against the cemeteries. Cases of an exceptionally unfavorable influence of a mass of decomposing matter on certain waters may occasionally occur, but none such have been established in the soils of Paris, and those which have been described in other places are not conclusive. What, on the contrary, most evidently comes out after a study of the facts is the remarkable purifying power that the earth possesses. It would take too long to give here the proof that water is not infected by cemeteries; we mention only the case of the well in the cemetery of Montparnasse, the water of which is shown by chemical analysis to be of excellent quality.

With respect to the inferior organisms which some persons believe may be conveyed away by water that has traversed the soil of cemeteries, we may say that M. Pasteur has shown that the waters of springs issuing from the ground even at a slight depth, are so destitute of germs that they can not fertilize the liquids which are most susceptible of change. Such waters, says M. Pasteur, "are at the base of lands which have been traversed incessantly for centuries by streams, the effect of which has been constantly to cause the finest particles of the superposed soils to descend to the springs. The latter, in spite of these favorable conditions for polluting them, remain indefinitely of a perfect purity, a manifest proof that a certain thickness of earth arrests all the finest solid particles."

The wells in Paris being hardly ever used, they ought to be infected by the nitrates which, supposed to be introduced into them, are not drawn from them. It is, however, far from being proved that the cemeteries contribute materially to the excess of nitrates in the well-waters, for the analyses we have made show no sensible difference from those which were made by M. Boussingault twenty years ago. The mean quantity is the same, and our partial results show sometimes a little less, sometimes a little more, saltness than those of M. Boussingault. Now, people have continued to bury, and the ultimate products of decomposition have become more and more soluble; and, if the excess of nitrates that has been observed was due to the cemeteries, it would of necessity have increased.

Besides the precise points which we have reviewed, more general and indeterminate accusations are made against the cemeteries. Such charges are connected with the prejudice, often ill-founded, under the influence of which we a priori attribute injurious properties to everything that smells badly. This error arises in part from the repugnant associations which are commonly attached to the substances and places from which bad smells emanate; but, while we admit that effluvia which offend the sense of smell are not agreeable, it is not true that such emanations are generally injurious to the public health.

The facts of this order, which have long served as the foundation of the accusations directed in the name of hygiene against the cemeteries, date from the last century, when chemistry and hygiene were still in the rough. No modern observation enforces them. On the contrary, contemporary scientists, who have studied the effects of animal putrefaction, are almost unanimous in regarding it as innocuous. Such is the opinion of the most authoritative modern authors, Dr. Warens, Bancroft, Andral, Parent-Duchâtelet, and, more especially with reference to cemeteries, Professors Depaul and Bouchardat.

It is hardly necessary to mention that a number of occupations expose those engaged in them to putrid exhalations, without producing injurious results upon them. Thus, soap-boilers and chandlers are known to enjoy excellent health, and not to be subject to fevers or epidemic affections, notwithstanding they often use fat in a very advanced stage of putrefaction (Tardieu). Tanners and curriers are neither more frequently nor more seriously ill than other men, aside from the occasional carbuncular affections they may acquire by real and direct inoculation, although they are often obliged, especially in summer, to work upon hides that are green with putrefaction. The same may be said for scavengers. The gases which, confined in pits, cause asphyxia, bring no diseases upon the men when a sufficient quantity of atmospheric air is present with them. Grave-diggers, instead of being more subject than other men to febrile, contagious, or epidemic diseases, have always been supposed to enjoy a certain immunity against them. Examples illustrating this principle are not wanting. A long catalogue of them might be cited without any trouble, except to the reader, to whom the reiteration would be tedious.

In conclusion, it may be affirmed that, to the present day, not a single instance of positive noxious infection has been laid to the charge of the cemeteries of Paris. We are in a situation, therefore, to reassure the public on this point, and to deplore with the illustrious Fourcroy "the abuses which certain persons have made of the discoveries in physics and chemistry, taking advantage of them to magnify and multiply complaints against the air of cemeteries and against its effects on the neighboring residences."

Let us say, if we have not courage to support it, that the spectacle of death ought to be hidden from our sight, that in our life of feverish industrialism we have no time to spare for the dead; let us even acknowledge that we have speculative reasons for desiring to remove the burial-grounds from Paris; but let us stop invoking science, let us stop invoking hygiene; let us stop asserting that cemeteries are real centers of infection, that they are susceptible of developing the germs of the gravest maladies; let us stop frightening the ignorant public with sonorous words and phrases. It is easy enough to say and repeat that cemeteries are a source of dangerous emanations, but assertions are not proofs.—Revue Scientifique.