Since the days of ancient Egypt, if not before, embalming has been part of the funeral process. The Egyptians embalmed for religious reasons, believing it necessary for to enter the afterlife, because once in the afterlife the decedent would need a body. During the American Civil War, embalming was done to preserve the bodies of troops so that they could be shipped back to their families for burial. Today we embalm our dead for preservation and restoration to a more pleasing appearance.
The Egyptian embalming process took about 70 days. It began with the body being washed and an incision cut into the side. Through this incision the internal viscera were removed and placed in canopic jars. The brain, accessed via the nose, was minced and pulled from the skull with hooks. Next the body cavity was stuffed with natron salt (sodium bicarbonate), the skull filled with resin, and then allowed to "cure" for a period of about 40 days. After these 40 days, the body was anointed with perfume and then packed with herbs, linen, and/or sawdust. Finally, the body was wrapped in linens and placed in a coffin for entombment.
Embalming began in America during the Civil War. Embalming his first body in 1861, Dr. Thomas Holmes, is credited as being The Father of Modern Embalming. MUCH less complicated and time consuming than the Egyptian method and the basis for modern embalming, arsenic mixed with water was injected through the arterial system. Arsenic effectively killed off microorganisms that contributed to decomposition but was banned in the early 20th century due to its significant health risks.