Dr. Lothes und Dr. Profé, "Zur unschädlichen Beseitigung von Thiercadavern auf dem Wege der Verbrennung", in: Berliner Thierärztliche Wochenschrift, Year 1902, No. 37, pp. 557 to 560
About the Safe Removal of Animal Carcasses through Burning
Dr. Lothes and Dr. Profé
Cologne on the Rhine
In the struggle against animal epidemics, the destruction of the infection hearths that are the carcasses of diseased animals plays an important part. The disease-causing germs remain alive and virulent in the carcasses or in their surroundings for a considerable time, so that certain accidental circumstances are sufficient for them to get into a new, receptive individual and unfold their pathogenic effect there.
The virus of rabies remains active in a carcass despite advanced decomposition for 4 to 6 weeks (Galtier). The glanders bacilli remain virulent in humid media for 3 to 4 weeks. One must therefore assume that they maintain their pathogenic effect about equally long inside the carcass.
Pieces of lungs of animals with lung disease maintain their infection capacity for several months if kept at low temperatures (Laguerrière).
Much more resistant than the aforementioned infection substances are those of anthrax. The agents of this disease under certain circumstances form the so extraordinarily resistant spores. There can be no doubt that also inside the cadaver anthrax spores form shortly after death. One the one hand, also if no postmortem is made, the emanation of blood from mouth, nose and anus, which regularly occurs in anthrax, offers an opportunity for this. One must further assume that the anthrax bacilli located in the skin's outside vessels receive the oxygen supply required to form spores.
Manifold observations confirm that the spores can return to the circulus vitiosus from the buried carcass. According to these observations the spores from graves may carry on even after years and decades in various ways, like for instance through the groundwater, in order to reach daylight again somewhere and again take up their destructive activity towards a new individual.
It should not be without interest to mention here briefly some experiments conducted in order to examine the permeability by anthrax spores of sand and gravel soils, i.e. the ones that are mainly present in practice, in the bacteriological laboratory of the Rhine Province's provincial administration.
1. Into an iron tube 1.75 meters long with a diameter of 0.1 meters, sealed with a wire net at its lower end, walnut-sized pebbles were introduced to a height of 10 centimeters, followed by a layer of hazelnut-sized pebbles also 10 centimeters high. Thereupon the tube was gradually filled with fine gravel sand, which was mixed with few pebbles about the size of a pea. After filling in 500 cubic centimeters of sand the tube's contents were pressed tight with a heavy wood block having a diameter of 8 cm and a length of 1.5 meters. After the gravel sand had reached a height of 1.50 meters, the tube was vertically fixed to a wall, and a glass bowl was placed below the lower end. Then 2 liters of tap water were gradually poured into the tube; after 48 hours about 1200 cubic centimeters of water had dripped into the glass bowl. Of this water respectively 25 plates were covered in 10 Petri double bowls with nourishment agar and placed in the incubator. After 24 to 36 hours numerous colonies were found: coli, proteus bacteria, cocci, among others - no anthrax colonies.
Now dry spleen pulp, which had been spread on object carriers for a period of some days to some weeks, was scratched off, dispersed on the upper layer of gravel sand and covered with 1.5 liters of water. After 36 hours, about 700 cubic centimeters had dripped into the glass bowl. Of these respectively 20 to 25 plates were covered with nourishment agar in 10 Petri double bowls and put into the incubator. After 36 hours several anthrax colonies were found on each plate.
An upright iron tube 2.2 meters long with a light width of 0.15 meters, sealed at the lower end with a wire net, was filled to a height of 0.2 meters with hazelnut- to walnut-sized pebbles and above those with fine sand to a height of 2 meters. The sand was gradually poured in small amounts and firmly pressed each time. Hereafter 2 liters of tap water were poured into the tube's upper end. After 48 hours 1,250 grams of water had penetrated the sand and pebbles and reached the glass bowl. Of this water respectively 20 plates were covered with nourishment agar in Petri double bowls and placed in the incubator. After 48 hours, the plates contained several colonies of cocci, tetrad, proteus and similar bacteria, sarcina, etc., but no anthrax colonies.
Hereupon anthrax spores were dispersed on the upper layer of sand and, after a sterile bowl had been placed below the tube, 2 liters of water were poured on them. After 30 hours, 1,100 grams of water were in the glass bowl. Of this water plate samples were taken in the manner described above and left for 24 hours at incubator temperature. After another 24 hours, 5 to 12 anthrax colonies could be detected in every double bowl.
After both tubes had been annealed and the glass bowls sterilized, the experiment was repeated with sand sterilized at high temperature and sterilized water; the result was the same. The anthrax colonies could regularly be detected in the water that had seeped through.
The above shows that anthrax spores can through water pass sand and gravel layers about 2 meters high within 30 hours on average, i.e. in a relatively very short time. As it is known that anthrax spores remain virulent in the ground for decades, the burial of anthrax carcasses means the conscious making of new infection hearths, which according to our current knowledge are almost impossible to destroy.
The Reich Law about Animal Diseases of 23 June 1880/1 May 1894, in its articles 26, 33, 39 and 43, provides for the safe removal of disease carcasses. The Federal Council's Instruction requires for anthrax (article 11) for rabies (article 33), for glander (article 40) and for lung disease (article 89) the safe removal by applying high temperatures, but also allows burial of the carcasses under certain conditions.
It is known that the removal of disease carcasses by applying high temperatures takes place in a very small number of cases, because due to the high costs incurred in building cremation ovens and installations for destruction of carcasses such installations are only available in the Reich sporadically and almost exclusively in the proximity of large cities.
In the rural districts, where animal epidemics occur in the first place, the carcasses are almost always buried, as the more recommendable solution of burning them in the open was until now generally considered non-executable.
In the Posen province in 1900/1901, Profé had several anthrax carcasses burned in an open fire with their owner's approval. The burning succeeded in a relatively short time and using rather low amounts of burning material if the fire was inside a pit and the corpse lay on iron rails running across the pit.
In July of this year, the district veterinary of the Cologne district had the opportunity of testing the burning procedure on an anthrax carcass. The carcass of a very well fed cow that had fallen victim to the disease had been taken to a field where mixed food was grown and there postmortem had been performed by the veterinary who had treated the animal. As the transport of the opened carcass to the community burial place could not be carried out and the carcass could also not be safely removed in another way, burning was ordered. The burning material, besides the petroleum used for ignition, was brown coal briquettes. After the carcass had completely caught fire, no more burning material was added, obviously for reasons of economy. Due to the abundant fat the burning process was nevertheless entertained. However, the burning of the carcass, weighing about 11 cwt, lasted about 40 hours. The costs incurred were about 3 marks.
Alerted to the practical usefulness of burning by the aforementioned trials, the authors in the summer of this year arranged the burning of several carcasses in open fire at the Cologne city burial site, in order to establish an adequate method and the required amounts of burning material as well as the cost thereof. About these trials and their results the following shall be reported hereafter:
I. On 15 July the skinned carcass of a horse together with the viscera, weighing 12 cwt, was burned in an open fire. The fire was burning inside a pit about 1 meter deep. The carcass was placed on two iron T-carriers two meters long placed across the pit. Besides low amounts of straw 2 cwt of wood, 3 cwt of briquettes and 25 kg of coal tar served as burning material. At first a ½ cwt of wood and 1 cwt of briquettes were set on fire below the carcass drenched in tar, the remaining part of the burning material being gradually added as necessary. The whole thing was set on fire at 6 hours in the afternoon. In the following afternoon at 2 hours, that is 20 hours later, only a weakly smoking heap of ashes was left. The smoke developed was considerable only as long as the tar was burning. The costs were 2.40 marks for 2 cwt of wood (at 1.20 marks per unit), 2.10 marks for 3 cwt of briquettes (at 0.70 marks per unit) and 2.25 marks for 25 kg of coal tar (at 0.09 marks per unit), altogether 6.75 marks.
II. On the same day a second horse weighing about 17 cwt without skin, but with the viscera in their natural place, was burned. For the burning, which was carried out in the same manner as described before, there were required, besides a little straw, 2 cwt of wood, 4 cwt of briquettes and 30 kg of American resin (at 0.14 marks per unit). The burning was complete only after 26 hours. The costs added up to 9.40 marks.
III. On 22 July a cow, which skinned with entrails weighed about 6 cwt, was also burned in the manner described above. Besides low amounts of straw 4 ½ cwt of wood and 15 kg of tar had been spent until complete combustion, which was complete after 8 ¼ hours. The price for the necessary burning material in this case was 6.75 marks.
We wish to point out right away that the resin did not manage to light the flame in the same manner as the tar. The effect of the occasionally used petroleum was also too little effective.
The three trials mentioned above showed the effect of the wind, which - independently of whether it hit the pit in the frontal or lateral direction - considerably pressed back flame and heat and unfavorably influenced the burning process. Thus, the pits serving the further burning were made deeper and the carcasses were also placed deeper. The preparations for the further trials were the following:
From the bottom of a pit 2 meters long, 2 meters wide and 0.75 meters deep there was made a second pit also 2 meters long and 0.75 meters deep, but only 1 meter wide, so that the upper pit's bottom simultaneously formed the side edges of the lower pit, 0.5 meters wide each. Onto these edges were lain the 2 meter long T-carriers transversally to the pit's longitudinal direction. On the carriers was placed the opened and eviscerated carcass, belly side down, so that one carrier lay immediately before the hind extremities, the other immediately behind the front extremities. Before this was done, a part of the burning material had been piled up on the lower pit's bottom. The viscera were left on the side edges, from where they were later, as the burning had progressed, gradually pushed into the blaze.
IV. A horse carcass placed in the manner described, which besides viscera had a weight of about 16 cwt, was burned on 13 August with wood alone, for the ignition of which very low amounts of straw were used. For complete combustion only 6.5 cwt of wood were required. The burning of the very massive and fatty carcass plus viscera was completed after 10 hours. The cost was 7.80 marks.
V. A horse carcass weighing 8.5 cwt, for the burning of which on 24 July, in the same manner as described above, 15 kg of tar and 4.5 cwt of wood besides low amounts of straw were required, took 5 hours and 40 minutes to combust completely. The costs for the burning material in this case were also 6.75 marks.
VI. A cattle carcass, which besides viscera weighed six cwt, was burned on 24 July in the same manner. Besides low amounts of straw 15 kg of tar and 3 cwt of wood were required for complete combustion. Combustion was completed after three hours and 30 minutes. The price of the required burning material was 4.95 marks.
It should be borne in mind that for the burning materials used big city prices were paid, and that the burning material, namely the wood, can be obtained much more cheaply in most rural districts.
Thus, two different burning methods have been applied. The carcasses I - III were placed in such a way that they were above ground, whereas the carcasses IV - VI were placed so as to be below ground.
The theoretical evaporation capacity of wood is a nine-fold, i.e. 1 kg of wood can evaporate 9 kg of water. The capacity of brown coal is a twelve-fold. If in the following calculation we leave the coal tar and the resin out of our considerations, which can be considered admissible as they were applied only in insignificant amounts and in an equal manner in both series of experiments, the experiments present the following picture:
I. For 600 kg of carcass 100 kg of wood, 150 kg of brown coal (and 25 kg of tar) = 2,700 evaporation units (E.U.) were required; per 1 kg = 4.5 E.U. The burning time was 20 hours; per kg 2 minutes.
II. For 850 kg of carcass 100 kg of wood, 200 kg of brown coal (and 30 kg of resin) = 3,300 E.U. were required; per kg 3.88 E.U. Burning time 26 hours; per kg 1.72 minutes.
III. For 300 kg of carcass 225 kg of wood (and 15 kg of tar) = 2,025 E.U. were required; per kg = 6.75 E.U. Burning time 8 hours and 15 minutes; per kg 1.65 minutes.
Thus on average 5.04 E.U. were required for 1 kg of carcass. A kilogram burned within 1.79 minutes on average.
IV. For 800 kg 325 kg of wood = 2,925 E.U. were spent; per kg = 3.65 E.U. Burning time ten hours; per kg = 0.75 minutes.
V. For 425 kg of carcass 225 kg of wood (and 15 kg of tar) = 2,025 E.U. were spent; per kg = 4.76 E.U. Burning time: 5 hours and 40 minutes.
VI. For 300 kg of carcass 150 kg of wood (and 15 kg of tar) = 1,350 E.U. were spent; per kg = 4.5 E.U. Time 3 hours and 30 minutes; per kg = 0.7 minutes.
Thus in these trials 4.3 E.U. and a burning time of 0.75 minutes per kg of carcass were required on average.
From the foregoing it follows that burning according to the second method, in which the carcass lies above the deeper pit in such a way that it is below ground surface, is the most adequate one. For one thing, it requires lower quantifies of heating material, and furthermore it takes much less time than the method initially applied.
By burning the carcasses in the two-part (sunken) pit one achieves, besides a better use of the burning material, a certain independence from the wind. As the pits must sometimes be made already on the day of postmortem, this advantage, having in view an eventual change of the wind direction, should not be underestimated.
The trials also show that the carcasses can be combusted in a relatively short time. Within one hour, according to the second method, 80 to 85 kg of carcass will combust. For burning 100 kg of carcass about 40 kg of wood or about 30 kg of brown coal or 24 kg of black coal are sufficient.
The choice of burning material is of course guided by the site where the burning is to happen. As a rule, the cheapest burning material will be used. For igniting the fire coal tar is to be recommended, with which not only the burning material should be impregnated, but also the carcass should be coated. We think that coal tar is especially recommendable also because it is easy to obtain and cheap. In relation to petroleum it furthermore has the advantage of being absolutely safe, a circumstance that under rural conditions deserves some consideration.
As concerns choosing the place of burning one need not be particularly scrupulous. In our trials we found that a stronger development of smoke takes place only at the start of the burning process. A considerable annoyance of the neighborhood is therefore not to be expected. The same applies regarding the burning gasses. The smell caused by the same was no longer perceptible 100 meters from the burning site in the prevailing wind direction. It should be taken into account, however, that the postmortem takes place on the site of burning. It is therefore recommended to in any case erect the respective site at a distance of some hundred meters from human habitations.
Briefly summarizing the above, we believe that on grounds of our trials we can recommend the following procedure for burning carcasses:
After digging in the bottom of a pit 2 meters long, 0.75 meters deep and 2 meters wide a second pit two meters long and 0.75 meters deep, but only 1 meter wide, the bottom of the latter pit is covered with straw drenched on tar (to keep blood from seeping through). Onto the straw burning material is piled until close to the upper pit's bottom. Some medium-size boards lain across the pits and 2 iron carriers or railway rails serve as base for the carcass taken there unopened and under observance of safety prescriptions. The carcass's postmortem is made lying on its back in the larger pit. After completion of postmortem the carcass is turned round, the cross boards are removed (and used for burning), so that the carcass's belly lies feely above the burning material. The straw at the pit's bottom is set on fire, after the viscera have been placed on the lower pit's side edges, from where they are gradually pushed into the blaze as the burning progresses. Burning material is added as required, until the carcass has been completely combusted. Hereupon the pit is again closed. Parts of the side edges that have been soiled by blood etc. are separated and placed directly on top of the glowing ash.
In this manner it is possible, and as we have seen with relatively limited means, to adequately carry out the safe removal of animal carcasses in districts where there is no cremation oven or destruction installation. Clinging to traditional methods will at first keep the burning of animal carcasses from being generally introduced. In case of epidemics it must however be promoted, for it is not compatible with the current status of veterinary hygiene that one constantly creates new hearths of infection by burning carcasses of diseased animals. When working over the Federal Council's Instruction regarding the Reich Law about Animal Diseases, the possibility of burying carcasses of diseased animals should, in the interest of combating animal diseases in general and anthrax in particular, be ruled out once and for all.
 Abbreviation of hundredweight, meaning a unit of 50 kilograms (translator's note).