Short answers, pulled from the story.
The Chinchorro culture began artificially preserving their dead as early as 5000 to 6000 BCE. This practice occurred thousands of years before the famous mummies of Egypt. The ancient artisans removed internal organs and muscles and replaced them with plant fibers and mud.
William Hunter applied the scientific understanding of blood circulation to the art of embalming as part of mortuary practice. His brother John Hunter advertised embalming services to the general public from the mid-18th century. William Harvey first detailed the system of blood circulation by injecting colored solutions into corpses.
The American Civil War drove the growth of embalming in the 19th century. Dr. Thomas Holmes received a commission from the Army Medical Corps to embalm the corpses of dead Union officers. The passage of Abraham Lincoln's body home for burial brought wider public attention to the possibilities of the practice.
Modern embalming fluids typically contain a mixture of formaldehyde, glutaraldehyde, methanol, humectants, and wetting agents. The formaldehyde content generally ranges from 5 to 35 percent. The methanol content may range from 9 to 56 percent.
Rosalia Lombardo died at age one on the 6th of December 1920 and is interred in the Capuchin catacombs of Palermo, Sicily. Her body is still perfectly intact and was embalmed by Alfredo Salafia. The body is displayed in a glass case and looks like a surreal doll.
Traditional Jewish law forbids embalming and burial is to be done as soon as possible, preferably within 24 hours. Members of the Bahá'í Faith are not embalbed and the body is washed and placed in a shroud. Islam does not practice embalming except in cases of necessity such as international transport.