Embalming is the process of preserving a corpse, typically so that it can be viewed at a funeral ceremony. Generally, when embalming does not occur within several days of a person's death, their body will begin to decompose. To ensure that this does not happen, preserving chemicals will be used so that the body of the deceased can be viewed at an open-casket funeral.
The process of embalming has a very long history, dating back to the Egyptian process of mummification. Though their techniques were quite different from those used today, the effect was the same — to preserve an individual's body after death. In case of the ancient Egyptians, they believed that the spirit would return to the body after death, so it must remain in good condition. To preserve the corpses, they covered bodies in a drying chemical called natron, and then wrapped them in linen sheets.
Today, embalming is done by injecting chemicals directly into the bloodstream to preserve the corpse's appearance. The most commonly used chemicals for embalming are formaldehyde and ethanol. A combination of these two chemicals is sufficient to preserve the body for a short time; to keep it in good condition for a longer period, you would use a solution made up almost entirely of formaldehyde.
Modern embalming came about during the American Civil War, in which many soldiers died in battle far away from their families. The families wanted an open casket funeral for their loved one, and so preserving techniques were approved so that the body would look as close to normal as possible for the funeral.
There are several steps involved in modern embalming. First, the embalming fluid is injected directly into the deceased's blood vessels, and pushed through the body with a mechanical pump. Next, the internal organs are hollowed of their contents and filled with embalming fluid. The chemicals are then injected beneath the skin wherever necessary, followed by a final surface embalming on injured areas of the body.
One of the most famous embalmed corpses today is Russian communist leader Vladimir Lenin, whose embalmed corpse is on display at the Red Square Mausoleum in Moscow. Curators at the Mausoleum say that the corpse is very well-preserved, and should last for at least another hundred years.