In most deliberate mummification traditions, internal organs were physically removed from the body, dried, treated with preservative substances, and either stored in separate containers or returned to the body cavity. The most famous example is ancient Egyptian practice, where embalmers made abdominal incisions to extract the lungs, liver, stomach, and intestines while intentionally leaving the heart in the chest. But mummification was never a single procedure, and the fate of the organs varied dramatically across cultures, time periods, and even social class. What happened to a pharaoh’s liver and what happened to a fisherman’s are two different stories, and both differ from what happened inside a frozen Inca child on a mountaintop or a Chinchorro infant on the coast of Chile thousands of years before Egypt’s first dynasty.
How Egyptian Embalmers Removed the Organs
The classical account, passed down from the Greek historian Herodotus, describes three tiers of mummification available at different price points. In the most expensive version, an embalmer made a long incision along the left side of the abdomen using a sharp stone, reached into the body cavity, and pulled out the major thoracic and abdominal organs one by one: the lungs, the liver, the stomach, and the intestines. In cheaper versions, Herodotus claimed, embalmers skipped the incision and instead injected cedar oil into the body through the rectum, then let it dissolve the organs internally before draining the liquid out.
Modern research has complicated this tidy picture. A radiological study comparing published descriptions of 150 mummies with CT data from additional specimens found that the neat division Herodotus described doesn’t hold up. Transabdominal evisceration wasn’t restricted to elites, and the cedar-oil enema method wasn’t reserved for commoners. The techniques varied by time period, the sex of the deceased, and local custom as much as by wealth or status.1PubMed Central. Radiological evaluation of the evisceration tradition in ancient Egyptian mummies The reality was messier and more creative than the stereotyped three-tier system the ancient texts suggest.
Getting the Brain Out
The brain received a different, somewhat rougher treatment. Egyptian embalmers didn’t consider the brain important for the afterlife. To remove it, they typically inserted a long metal hook or rod through one of the nostrils, punctured through the thin bone at the base of the skull, and then broke up the brain tissue inside the cranial cavity. The liquefied remains were drained out through the nasal passage, sometimes with the body tilted face-down.2PubMed Central. The importance of the nasopharynx and anterior skull base in excerebration techniques from KV40, a New Kingdom Egyptian site
Not every mummy was excerebrated, though. CT scans of three child mummies from the Graeco-Roman period revealed that despite earlier reports claiming the children had been excerebrated and eviscerated, no incisions or breaches of the cranial cavity were actually visible. The brain and internal organs were still in place.3Anthropologischer Anzeiger. The advantage of CT scans and 3D visualizations in the analysis of three child mummies from the Graeco-Roman Period This is a good reminder that generalizations about “the Egyptian method” paper over enormous variation. Children, people from certain periods, and individuals from lower-status burials sometimes received mummification with their organs intact or partially intact.
Why the Heart Stayed Behind
The heart occupied a unique position in Egyptian belief. It was regarded as the seat of intelligence, emotion, and moral character. In the mythology of the afterlife, the heart would be weighed against the feather of Ma’at (truth and justice) before the god Osiris. If the heart was lighter than or equal to the feather, the deceased could proceed to the afterlife. If not, a monster devoured it, and the person ceased to exist. Removing the heart would have meant stripping the dead of their identity and their chance at eternal life.
CT investigations of Egyptian mummies have confirmed that embalmers deliberately preserved the heart in the chest. In one study, preserved heart muscle was identified in nine mummies as a mostly shrunken but still recognizable structure.4PubMed. Preservation of the heart in ancient Egyptian mummies: A computed tomography investigation with focus on the myocardium In another case, researchers produced the first three-dimensional reconstruction and 3D print of a mummified heart from a person embalmed roughly 2,700 years ago, demonstrating that the organ retained enough structure to be digitally modeled and physically reproduced.5PubMed. Holding Eternity in One’s Hand: First Three-Dimensional Reconstruction and Printing of the Heart from 2700 Years-Old Egyptian Mummy The heart’s survival in these cases speaks to both the care embalmers took and the effectiveness of desiccation in preserving dense muscular tissue.
What Happened After the Organs Came Out
Once removed, the organs didn’t just get tossed aside. In the most well-known Egyptian practice, each major organ was dried in natron (a naturally occurring mineral salt), wrapped in linen, and placed in a canopic jar. Traditionally, four jars were used, each guarded by one of the four sons of Horus: Imsety protected the liver, Hapy the lungs, Duamutef the stomach, and Qebehsenuef the intestines. The jars’ lids were carved to represent the heads of these protector gods.
Molecular analysis of the canopic jars associated with Ramesses II revealed traces of the substances used during the process, including pure vegetable resin from Pistacia trees found stored with glued linen inside one of the jars.6Journal of Archaeological Science. The canopic jars of Rameses II: real use revealed by molecular study of organic residues This resin wasn’t decorative. It served a preservative function, helping to slow microbial decay of the organ tissue packed inside.
Over time, practices shifted. During the later periods of Egyptian mummification, embalmers sometimes dried and wrapped the organs and then tucked them back into the body cavity instead of using canopic jars at all. Some mummies have been found with organ packages placed between the legs or stacked in the abdomen. The canopic jars in these cases might still be placed in the tomb, but they were empty, functioning as symbolic containers rather than practical storage.
The Chemistry That Preserved Them
The central preservative agent was natron, a mixture of sodium carbonate and sodium bicarbonate with smaller amounts of sodium chloride and sodium sulfate, found in dried lake beds in Egypt. Natron works by aggressively pulling water out of tissue. Bacteria and the body’s own enzymes need water to break down tissue. Remove enough water fast enough, and decay stalls.
Experimental work has confirmed that natron outperforms ordinary salt for this purpose. In one study comparing heart tissue dried in natron versus heart tissue dried in sea salt, the natron sample dehydrated faster, and microscopic examination showed that the tissue architecture was better preserved in the natron sample.7Journal of Biological Research – Bollettino Della Società Italiana Di Biologia Sperimentale. Why did the Egyptians use natron for artificial embalming? An experimental study on organ mummification The researchers suggested that ancient Egyptians discovered natron’s advantage through trial and error over generations.
A more recent experimental mummification study, which followed the ancient literary sources as closely as possible, first dehydrated tissue specimens in artificial natron and then applied natural ointments. After seven weeks, mummification was considered complete in all specimens. The researchers observed substantial loss of weight and volume, along with similar patterns of tissue-architecture decay but varying levels of DNA degradation across sample types.8PubMed Central. Experimental mummification-In the tracks of the ancient Egyptians
Natron wasn’t the only active ingredient, though. The resins, oils, and bitumen applied to bodies and organs had their own antimicrobial punch. Testing of embalming fluids from the 18th Dynasty found that natron at about 11% concentration, palm wine, and pine resin all showed antibacterial activity. The natron solution and palm wine both produced zones of bacterial inhibition larger than those of a standard antibiotic used as a control, and the natron was effective against both major classes of bacteria.9Journal of Archaeological Science: Reports. A preliminary study on the antibacterial activity and insect repellent properties of embalming fluids from the 18th Dynasty (1550–1292 BCE) in ancient Egypt Separately, analysis of material matching the ancient description of liquid “cedrium” (a cedar-derived preparation) extracted from a mummified torso showed powerful bactericidal and fungicidal activity, with a compound called guaiacol identified as the most effective conserving agent.10Archaeometry. HERODOTUS’ AND PLINY’S EMBALMING MATERIALS IDENTIFIED ON ANCIENT EGYPTIAN MUMMIES
Petroleum bitumen also played a growing role, particularly in later periods of Egyptian mummification. Its use increased over time for both practical reasons, including its own antimicrobial properties, and cultural ones.11PubMed Central. The significance of petroleum bitumen in ancient Egyptian mummies The dark coating it left behind is, in fact, where the word “mummy” comes from: the Arabic word for bitumen, “mumiya.”
Not Every Culture Removed the Organs
Egyptian-style evisceration is the most famous approach, but it isn’t the only way humans have dealt with internal organs in mummification. The Chinchorro people of what is now coastal Chile and Peru practiced artificial mummification roughly 7,000 years ago, thousands of years before the earliest known Egyptian mummies. Their morticians removed internal organs and sometimes defleshed the body entirely. In later Chinchorro periods, they made incisions to extract major organs and then filled the body cavities with plant fibers, sticks, clay, and soil to restore the body’s shape.12Cambridge University Press. The Artistic Nature of the Chinchorro Mummies and the Archaeology of Grief The emphasis was on reconstructing the body’s exterior form rather than preserving the organs themselves for an afterlife.
At the other extreme, some of the best-preserved internal organs ever found belong to mummies that were never deliberately prepared at all. The Llullaillaco mummies, three Inca children found near the summit of a volcano in Argentina at over 6,700 meters, were frozen shortly after death roughly 500 years ago. CT scans showed internal organs in remarkably good condition, with only natural shrinkage from dehydration. Both white and gray matter were clearly visible in the brain and cerebellum. The lungs were still expanded. Fatty tissue had transformed into a waxy substance, likely through a process called saponification, and calcium salts had deposited in the tissues.13PubMed. Radiologic evaluation of the Llullaillaco mummies Cold and altitude did what years of Egyptian embalming chemistry aimed for: they stopped biological decay almost completely, organs and all.
Natural mummification in other environments can preserve organs too, though less consistently. CT scans of thirteen naturally mummified bodies from 16th-to-18th-century Italy found that meningeal membranes (the coverings around the brain and spinal cord) were the most consistently preserved tissue, identifiable in all heads examined. Tendons of the hands and feet also survived well. But the soft tissues of the torso and legs had often collapsed into a formless mass, and organ preservation scores were very low overall.14PubMed Central. CT Scan of Thirteen Natural Mummies Dating Back to the XVI-XVIII Centuries: An Emerging Tool to Investigate Living Conditions and Diseases in History Without deliberate chemical treatment or extreme cold, organs in the abdomen and chest are usually the first structures to lose recognizable form.
How Well Do Mummified Organs Hold Up Under a Microscope
One of the more surprising aspects of mummified organs is that they can retain identifiable cellular structures, not just vague tissue outlines, for centuries or even millennia. Histological analysis of a medieval Korean mummy found that while collagen fibers dominated the preserved organ samples, specific cell types were still visible: red blood cells, cartilage cells, liver cells, and muscle cells could all be identified in various tissues.15PubMed. Histological analysis on the medieval mummy in Korea
In experimental mummification work on fresh human tissue using methods modeled on ancient Egyptian practice, histological analysis showed very good preservation of skin and muscle. In muscle samples, some structural breakdown was visible, particularly in the outer connective tissue sheath, while in skin samples the outermost layer was most affected.16PubMed. Modeling ancient Egyptian mummification on fresh human tissue: macroscopic and histological aspects The experimentally mummified samples actually showed better preservation than authentic ancient Egyptian tissue sections, suggesting that time and tomb conditions take their own toll even after mummification is “complete.”
Getting mummified tissue ready for microscopy is itself a technical challenge. Desiccated tissue is brittle and often too distorted to slice and stain directly. Researchers have developed specialized rehydration protocols, testing various solutions to restore enough flexibility for sectioning. Different tissues respond best to different rehydration and fixation combinations: what works for mummified placenta doesn’t necessarily work for mummified skin.17PubMed. Determination of optimal rehydration, fixation and staining methods for histological and immunohistochemical analysis of mummified soft tissues
What Preserved Organs Reveal About Ancient Disease
When organs survive, they become medical records. Paleopathologists have used preserved organs to diagnose diseases that would be invisible in skeletal remains alone. Lung tissue from Egyptian mummies has yielded some particularly striking findings. A study of six lung specimens from Egyptian mummies found focal areas of calcification consistent with old tuberculosis in two of the samples, along with evidence of pulmonary edema, emphysema, and pneumonia.18PubMed. Tissue identification and histologic study of six lung specimens from Egyptian mummies
A broader review of diseases identified in canopic jar contents and preserved organs over a century of research found that infectious diseases and internal medicine conditions dominated the findings, with schistosomiasis (a parasitic infection still common in Egypt today) and emphysema among the most frequently identified.19Pathobiology. Egyptian Canopic Jars at the Crossroad of Medicine and Archaeology: Overview of 100 Years of Research and Future Scientific Expectations These are diseases that specifically target internal organs rather than bones, which means they would be completely invisible if the organs had not been preserved. Canopic jars, originally created for religious reasons, have become accidental biomedical archives.
Molecules That Outlast the Cells
Beyond cell structure, mummified organs can preserve molecules that researchers use to reconstruct diet, ancestry, and disease at a biochemical level. Proteins and DNA can survive in desiccated tissue for thousands of years under the right conditions, though how much survives and in what condition varies enormously. Research on ancient tissue samples, including Neanderthal specimens, has shown that certain protein breakdown products serve as a reliable index of how much peptide hydrolysis has occurred, and by extension, how well DNA has been preserved. Cooler temperatures dramatically improve the odds: samples from arctic and subarctic regions consistently retain the most intact biomolecules.20PubMed. Protein preservation and DNA retrieval from ancient tissues
This has practical implications for what can be learned from different types of mummies. An Egyptian mummy stored in a hot, dry tomb for three millennia may yield identifiable tissue architecture and some protein fragments but badly fragmented DNA. A frozen mummy from a high-altitude site or a northern bog, preserved for a fraction of that time, may yield intact enough DNA for full genomic sequencing. The organs are preserved in both cases, but the molecular information accessible within them differs by orders of magnitude depending on the thermal history of the remains.
Which Organs Resist Decay the Longest
Even without deliberate mummification, not all organs break down at the same rate. The prostate and the nulligravid uterus (a uterus that has never carried a pregnancy) are among the last organs to decompose in a human body. Part of the reason is structural: the uterus has an unusually high content of muscle fiber, and both organs are coated in collagen that only a limited number of bacterial species can break down.21Frontiers in Microbiology. Effects of Extended Postmortem Interval on Microbial Communities in Organs of the Human Cadaver At the other end of the spectrum, the intestines and stomach, loaded with bacteria even during life, are among the first to putrefy.
This natural hierarchy of decay helps explain some of the patterns seen in mummies where organ preservation was left partly to chance. Dense, muscular, collagen-rich organs tend to survive, while hollow, bacteria-laden organs tend to disappear. When embalmers removed the intestines and stomach first and packed the body cavity with natron, they were working with the grain of biology: taking out the organs most prone to putrefaction and chemically treating the ones most likely to survive on their own. Whether they understood the microbiology behind it is unknowable, but empirical observation over generations would have made the pattern obvious enough.