Covering whole eggs in butter??

[liirogue]

In the Book Enemy Women by Paulette Jiles, it is said that you can cover “each egg with a thin film of butter and they will keep indefinitely, even in the hottest weather.” (pg. 191, hardback edition). This story is set during the US Civil War (circa 1860-1865). Is this true? Or was this true just for the times? If so, why?

[chukhung]

This page, http://www.aeb.org/eggcyclopedia/preservation.html, on the American Egg Board’s site says

[C]enturies before modern methods of egg production, transportation and refrigeration became known, man did his ingenious best to preserve the egg intact.
…
Immersion in different liquids too numerous to mention was explored, lime water being a favorite in the 18th century. During the early 20th century, water glass was used with considerable success. Water glass, a bacteria-resistant solution of sodium silicate, discouraged the entrance of spoilage organisms and evaporation of water from eggs. It did not penetrate the egg shell, imparted no odor or taste to the eggs and was considered to have somewhat antiseptic properties. However, it did a rather poor job at relatively high storage temperatures. Eggs preserved in a water glass solution and stored in a cool place keep 8 to 9 months.
…
In an attempt to seal the shell pores to prevent loss of moisture and carbon dioxide, a great variety of materials including cactus juice, soap and shellac were investigated with varying degrees of success. The only coating considered fairly efficient was oil which is still used today.

[OldBroad]

One caveat if you try this: Use only eggs that have not previously been refreigerated.

Offshore sailors keep eggs this way by coating them with Vaseline.

[aeropl]

OldBroad, Why do the eggs have to be previously unrefrigerated?