Adventuring into the Dead
The Story of Egyptian Embalming
Ever since the ancient Egyptians, people have been successfully embalming their dead.
One such method included the process of removing all the brain tissue from the nostrils, eviscerating all the internal organs through an incision through the flank, and anointing the interior of the body before re-closing the incision; the incision is then covered in beeswax to produce a less obvious scar. Afterward, they used natron to dehydrate the body before the remains were wrapped in many layers of linen cloths and resin. Natron was a mixture of Sodium chloride, sodium sulfate, sodium carbonate, potassium, and sodium nitrate. The process took about 70 days.
Pickling the Persians
Ancient Persians preserved their dead by immersing the bodies in jars of honey and wax, thus eliminating damaging air and microbes.
Leonardo DaVinci described a method of venous injection to preserve the cadavers he was studying. Early embalming fluids commonly contained mixtures of turpentine, camphor, lavender oil, and vermilion (mercury sulfide), wine, rosin, and saltpeter.
Gabriel Clauderus published a book on an embalming method involving balsamic spirit, which was a pound of cream of tartar and a half pound of salammoniac, dissolved in six pounds of water. This was injected into the body, and the body was then immersed in this mixture for 6 weeks, and then placed into the sun to dry.
In 1850, a psychotic man created a refrigerator for storing the dead bodies, which would delay decomposition, but would do nothing to stop the harmful bacteria.
Fun with Formaldehyde
By the early 1900's, laws prohibiting the use of metal salts in embalming were passed. Formaldehyde soon became the compounds of choice and has continued to be the most common preservative in embalming fluids. A German physician named Ferdinand Blum worked with a 4% aqueous solution of formaldehyde and discovered that his fingers would become stiff. He wrote a paper about his findings, and this began the widespread use of formaldehyde as a cell preservative.
The reasons for formaldehyde's continued use and popularity include it's low cost, availability, and simplicity of use. In addition, it provides good cell preservation under a variety of pH conditions.
In aqueous solutions, formaldehyde undergoes two reactions. The first part involves the formation of methylene glycol, which preserves tissue. In the second reaction, formaldehyde reacts with oxygen to yield formic acid. The presence of the latter in any great amount is unacceptable because it creates 'formaldehyde pigments' on the body. Chemicals such as methanol, methyl salicylate, and a variety of buffers are added to embalming fluids to prevent excess formic acid formation. Formaldehyde preserves tissue by forming cross-links among protein ends to create a stable, complex matrix. However, the exact mechanism of this cell fixation is unknown.
The small size of the formaldehyde molecule allows for rapid tissue penetration which is important because it helps decrease autolysis.
Formaldehyde is presumed to be carcinogenic and can cause "occupational asthma" and contact dermatitis. It also has a tendency to dry out tissue and can cause an ashen-grey coloration of skin.
One such chemical that was sought to replace formaldehyde was an embalming fluid containing dialdehyde, goxyal. However, this chemical was said to proudce a yellow stain on tissues and its popularity declined.
Another chemical introduced was glutaraldehyde which was first used in 1955. This substance was found to act similar to that of formaldehyde but without significant tissue dehydration. Factors such as concentration, pH, and temperature effected the efficiency of this chemical. Glutaraldehyde also diffuses and penetrates into tissue more evenly thus giving the body the ability to retain its natural texture and coloration. It is overall a more efficient and effective disinfectant that helps firm body tissue more readily and evenly.
In spite of glutaraldehyde's many glory's, formaldehyde is still the embalming fluid of choice in the United States; for reasons such as that it is a we accepted standard in the embalming history, it is 5-8 times less expensive on a per-pound base, and it has a lower toxicity. Formaldehyde still unfortunately has a rotten smell, but you have to compromise somewhere I suppose!