Putrefaction

Putrefaction refers to a process of breaking down the body of an animal just like a human post-mortem (that means after death). In other words, it can be regarded as the decomposition of proteins, and the gradual breakdown of the cohesiveness between tissues, and the liquefaction of major organs. This is led by the decomposition of organic matter via bacterial or fungal digestion, that results in the release of gases which can infiltrate the body’s tissues, and results in the deterioration of the tissues and organs. The approximate time taken for the putrefaction process to occur is based on various factors. Internal factors that mainly affect the rate of putrefaction including the age at which death has occurred, the overall structure and condition of the body, the reason of death, and external injuries that aroused before or after death. External factors also comprise some factors such as environmental temperature, moisture and air exposure, clothing, burial factors, and light exposure. The first signs and symptoms of putrefaction are signified by a greenish discoloration on the outer portion of the skin on the abdominal wall corresponding to where the large intestine starts, as well as under the  surface of the liver.

Some substances, like those of carbolic acid, arsenic, strychnine, and zinc chloride, can also be used to delay the process of putrefaction in different ways depending upon their chemical make up.

Process of Putrefaction

Continuous biochemical maintenance is mainly required to utilise the chemical energy of the body. When this condition is not maintained then it begins the process of hydrolysis. The hydrolysis of proteins to form water and amino acids is usually a spontaneous process and this process can be activated by various bacteria that are found in the human gut. This results in weakening and breaking of the tissues of the body. With continuous  breakdown of proteins, certain specific organic compounds and gases are excreted out by the bacteria, these emit a foul smell like that of rotten flesh.

At the time of this process, the skin tissues of the body get ruptured with the release of the bacterial gas. Due to the continued process of putrefaction, the body finally reaches a stage referred to as skeletonization in which only the skeleton of the body is left.

Factors affecting Putrefaction

Exogenous or External Factor

Environmental temperature: Decomposition process is usually activated by high atmospheric or environmental temperature, the putrefaction speed is maintained between 21 °C (70 °F) and 38 °C (100 °F), further the speed can be increased as the levels of humidity rise. This optimum temperature helps in the chemical breakdown of the tissue and further promotes the growth of microorganism.  Decomposition process generally stops below 0 °C (32 °F) or above 48 °C (118 °F).

Moisture and air exposure: Putrefaction process is usually slowed down when the body is submerged in water, this is due to the diminished exposure to air. Air exposure and moisture both function in the introduction and growth of microorganisms, and further accelerate the degradation process. In a hot and humid environment the body is able to undergo a process called mummification in which the BOD gets entirely dehydrated and bacterial decay gets inhibited. 

Clothing: Loose-fitting clothing can be used to speed up the rate of putrefaction, since it helps to retain body heat. Tight-fitting clothing might delay the process by cutting off blood supply to tissues and eliminating nutrients for bacteria to feed on.

Manner of burial: fast burial can slow down putrefaction. Bodies buried within deep graves decompose very slowly because of the diminished effects of changes in temperature. The composition of graves is also another major contributing factor, possessing dense, clay-like those of soil tending to accelerate putrefaction whereas dry and sandy soil retards it.

Light exposure: Light also acts as a contributing factor indirectly, since flies and insects prefer to lay eggs in areas of the body not exposed to light, like the crevices formed by the eyelids and nostrils.

Endogenous (internal)

Age at time of death: foetuses and infants putrefy gradually due to their sterility. Although, younger people putrefy more rapidly than older people.

Condition of the body: A body having a greater fat percentage and less body mass will possess a faster rate of putrefaction, since fat retains more heat and it carries a huge amount of fluid in the tissues.

Cause of death: The cause of death possesses a direct relationship to the speed of putrefaction, with bodies that die with acute violence or accident usually putrefy slowly than those that died from any infectious diseases. Some poison, like those of potassium cyanide or strychnine, might also delay putrefaction, whereas chronic alcoholism will speed it.

External injuries: the main function of the post-mortem injuries is to speed putrefaction since the injured areas might be more susceptible to invasion by bacteria.

Delayed putrefaction

Some poisonous substances present in the body delays the process of putrefaction. They comprise:

• Carbolic acid (Phenol)

• Arsenic and antimony[6]

• Strychnine[6]

• Nux vomica (plant)

• Zinc chloride, ZnCl2

Applications of Putrefaction

In Alchemy, putrefaction functions the same as fermentation, where a substance is allowed to rot or decompose undisturbed. In few cases, the beginning of the process is facilitated with a small sample of the desired material that acts as a “seed”, it is a technique which involves the use of a seed crystal in the process of crystallization.

Conclusion

After death, a series of changes occurs naturally in the human body. Though these changes occur in an orderly way, a variety of external factors and intrinsic factors help to accelerate the rate of decomposition. With this we come to an end of this topic, hope you were able to grasp a clear concept of putrefaction.