Why is "six feet under" the standard depth for burial?
I'm trying to find the origin for the practice of burying bodies six feet underground. Why is this particular depth so popular that it's become synonymous with having shuffled off the mortal coil? I'm sure there's a rotting-corpse stink factor in the story somewhere.
Let's lay to rest the idea that in the present day we must bury our dead deep to avoid stench or health crisis. Mark Harris, former environmental columnist for the Los Angeles Times, points out that "in the typical modern burial, the body is pumped full of toxic embalming chemicals [and] sealed inside a metal casket that’s entombed within a concrete bunker," presumably making it an unlikely spot for disease to find any serious foothold.
That's just common sense, of course; in search of some real inside dirt I called Mike Miller, a funeral planner at Metcalf & Spilsbury Mortuaries in Saint George, Utah. He listened gravely (OK, OK, I'll cut it out) to my inquiries before informing me that, sure enough, there's no minimum safe depth at which a body must be planted – burial depth can vary from 1.5 to 12 feet, sometimes even deeper. Individual jurisdictions specify their own minimum depths, but most are nowhere near six feet. In California, for example, the coffin must be covered by a minimum of 18 inches of dirt and turf; Quebec's Burial Act orders that “the coffin shall be deposited in a grave and covered with at least 1 m of earth, but the Minister of Health and Social Services may, in special cases, dispense with the application of this section.” (It's common today, too, for couples to be buried in the same grave, with one casket below the other.)
In low-lying wetland areas like New Orleans, Miller noted, a grave dug six feet deep would likely fill with water. Graves in such locales are typically less than two feet deep, reducing (but not eliminating) the coffin's chances of gradually floating toward the surface. Early New Orleanians tried to keep the dead safely out of the way by weighing caskets down with rocks, but even so the airtight coffins would sometimes come popping up out of the soil. Today, in areas well above the water table and generally considered safe from flooding, heavy rains will still dislodge the occasional coffin. Miller added that as the price of scarce cemetery land skyrockets, above-ground interment in existing vaults and mausoleums is becoming increasingly popular; cremation, which typically costs something like $1,800, is also making gains on traditional burial, which might well run $10,000.
That settled, where did the famed figure come from? Historians believe it dates to London's Great Plague of 1665. In Daniel Defoe's fictionalized account A Journal of the Plague Year, the diarist-narrator reports on an edict issued by the city's lord mayor in June 1665 requiring that all graves be made at least six feet deep to limit the spread of the outbreak. Even if Defoe's research wasn't perfect (his firsthand knowledge may have been less than reliable, as he was only five at the time of the epidemic), other sources largely back up his version of events; in any case, his book likely popularized the notion that proper burial entailed putting the body six feet under.
As a reward to myself for having resisted making lots more burial-related puns, I'll just mention that lawyers are buried 24 feet underground rather than 6. Why? Because deep down, they're real nice people.
Colman, Penny, Corpses, Coffins, and Crypts: A History of Burial (1994)
Iserson, Kenneth, Death to Dust: What Happens to Dead Bodies? (2001)
Jackson, Percival, The Law of Cadavers and of Burial and Burial Places (1936)
(Thanks to SDSAB member Gfactor for his assistance with sources.)