Is That Grave-Wax On Your Collar
...Or are you just happy to see me?
DECOMPOSITION AND SKELETONIZATION
The breakdown of soft tissues and non-mineral components of bone occurs as a series of processes that begin at death. What was a dynamic, organized chemical system (the living organism) becomes less organized and more susceptible to outside influences. In many environments, the soft tissue ultimately liquifies and becomes separated from the bone. The mineral constituents of bone and teeth are much slower to decompose. Eventually, as soft tissue is lost, the skeleton may become completely exposed or skeletonized. In freezing or very dry environments, soft tissue may not be lost and skeletonization may not occur or may be incomplete.
Temperature is the most important variable influencing the speed of decomposition. Chemical processes in living mammals are optimal near 37 degrees Celsius. Heating or cooling relative to that temperature will speed or slow the enzyme systems that control cell metabolism. At high temperatures (around 60 degrees Celsius) enzymes break down into their constituent amino acid chains and fragments (Gill-King, 1997). Freezing temperatures may halt most biochemical reactions.
If a body is placed in water, changes in temperature may be buffered and the pH may be altered. Depending on whether the water is salty, fresh, moving, or of a certain pH, the speed of decomposition in a submerged body may be faster or slower. Bodies in moister settings are more likely to give off scent because decomposition gases are water soluble. High levels of moisture also may encourage the formation of adipocere (also called grave-wax), as well as the growth of some plants and bacteria.
If bodies are in oxygen-deprived environments, such as in water, deeply buried, or at high altitude, decomposition may be slowed. Many bacteria are anaerobic, however, and low oxygen levels may actually stimulate their growth. In fact, autolysis, which occurs early on in cell death, results from lack of oxygen needed by enzymes. As a body goes through early autolysis, it also undergoes rigor mortis, with muscles stiffening, about 26 hours after death. At 46 hours it spreads to all the muscles, and remains in place for about 2484 hours (Gill-King, 1997). In cooler temperatures, rigor occurs earlier and stays longer; warm temperatures can delay its onset or even keep it from developing completely.
At the end of the autolysis phase the system becomes very anaerobic. Bacteria in the large intestine and in surrounding soil grow rapidly, degrading the cells around them, and producing bloating, color change, and odor. This is the putrefaction and fermentation phase. Proteins are broken down to amino acids. The result of these processes is the presence of several toxic and volatile substances, including hydrogen sulfide, methane, putrescine, and cadaverine. The latter two produce the characteristic foul odor detectable by cadaver dogs (Gill-King, 1997). (These substances can be absorbed through unprotected skin and can compete with oxygen in respiration, requiring care on the part of recovery workers, particularly in closed and poorly ventilated settings.)
The bowel remains intact for some time as gases are produced, creating bloating. The bloating can cause a burial surface to rise, and can cause submerged bodies to float. In either of these cases, the temperature of the soil or surrounding water may be cold, delaying putrefaction. Bodies may remain submerged for several months of winter, rising to the surface only when spring warms the waters. If in very deep water, the body may never float.
Putrefaction causes dramatic color changes. Breakdown of hemaglobin produces the pigments biliverdin (which is green) and bilirubin (which is red) and subsequently urobilin (which is brown). Biliverdin in the skin may be converted to blue and yellow pigments. Hydrogen sulfide in the intestines can combine with iron to produce ferrous sulfite (black).
Adipocere, a waxy substance of varying consistency, may form within days or months given sufficient fats and moisture in the decomposition environment. Individuals who have a higher proportion of fat (such as obese individuals, more women than men, and infants) are more likely to produce adipocere. Not all bodies will produce it. In environments with more mineral content in soil or water, the adipocere is likely to be harder. It otherwise varies in texture from more crumbly to more paste-like.
-Cadaver Dog Handbook by Andrew Rebmann, Edward David, and Marcella H. Sorg
I doubt I'll ever read through the whole thing but certain passages will be examined until my curiosity abates.
DECOMPOSITION AND SKELETONIZATION
The breakdown of soft tissues and non-mineral components of bone occurs as a series of processes that begin at death. What was a dynamic, organized chemical system (the living organism) becomes less organized and more susceptible to outside influences. In many environments, the soft tissue ultimately liquifies and becomes separated from the bone. The mineral constituents of bone and teeth are much slower to decompose. Eventually, as soft tissue is lost, the skeleton may become completely exposed or skeletonized. In freezing or very dry environments, soft tissue may not be lost and skeletonization may not occur or may be incomplete.
Temperature is the most important variable influencing the speed of decomposition. Chemical processes in living mammals are optimal near 37 degrees Celsius. Heating or cooling relative to that temperature will speed or slow the enzyme systems that control cell metabolism. At high temperatures (around 60 degrees Celsius) enzymes break down into their constituent amino acid chains and fragments (Gill-King, 1997). Freezing temperatures may halt most biochemical reactions.
If a body is placed in water, changes in temperature may be buffered and the pH may be altered. Depending on whether the water is salty, fresh, moving, or of a certain pH, the speed of decomposition in a submerged body may be faster or slower. Bodies in moister settings are more likely to give off scent because decomposition gases are water soluble. High levels of moisture also may encourage the formation of adipocere (also called grave-wax), as well as the growth of some plants and bacteria.
If bodies are in oxygen-deprived environments, such as in water, deeply buried, or at high altitude, decomposition may be slowed. Many bacteria are anaerobic, however, and low oxygen levels may actually stimulate their growth. In fact, autolysis, which occurs early on in cell death, results from lack of oxygen needed by enzymes. As a body goes through early autolysis, it also undergoes rigor mortis, with muscles stiffening, about 26 hours after death. At 46 hours it spreads to all the muscles, and remains in place for about 2484 hours (Gill-King, 1997). In cooler temperatures, rigor occurs earlier and stays longer; warm temperatures can delay its onset or even keep it from developing completely.
At the end of the autolysis phase the system becomes very anaerobic. Bacteria in the large intestine and in surrounding soil grow rapidly, degrading the cells around them, and producing bloating, color change, and odor. This is the putrefaction and fermentation phase. Proteins are broken down to amino acids. The result of these processes is the presence of several toxic and volatile substances, including hydrogen sulfide, methane, putrescine, and cadaverine. The latter two produce the characteristic foul odor detectable by cadaver dogs (Gill-King, 1997). (These substances can be absorbed through unprotected skin and can compete with oxygen in respiration, requiring care on the part of recovery workers, particularly in closed and poorly ventilated settings.)
The bowel remains intact for some time as gases are produced, creating bloating. The bloating can cause a burial surface to rise, and can cause submerged bodies to float. In either of these cases, the temperature of the soil or surrounding water may be cold, delaying putrefaction. Bodies may remain submerged for several months of winter, rising to the surface only when spring warms the waters. If in very deep water, the body may never float.
Putrefaction causes dramatic color changes. Breakdown of hemaglobin produces the pigments biliverdin (which is green) and bilirubin (which is red) and subsequently urobilin (which is brown). Biliverdin in the skin may be converted to blue and yellow pigments. Hydrogen sulfide in the intestines can combine with iron to produce ferrous sulfite (black).
Adipocere, a waxy substance of varying consistency, may form within days or months given sufficient fats and moisture in the decomposition environment. Individuals who have a higher proportion of fat (such as obese individuals, more women than men, and infants) are more likely to produce adipocere. Not all bodies will produce it. In environments with more mineral content in soil or water, the adipocere is likely to be harder. It otherwise varies in texture from more crumbly to more paste-like.
-Cadaver Dog Handbook by Andrew Rebmann, Edward David, and Marcella H. Sorg
I doubt I'll ever read through the whole thing but certain passages will be examined until my curiosity abates.