Dissolve one ounce of Alum in a half pint of Vinegar. Use a small
pointed brush to outline whatever design or write whatever words
you want on the shell of an egg. After the solution has dried out
thoroughly on the egg, boil it for about 15 minutes.
If you follow these directions the design will disappear from the
outside of the shell but the writing will plainly show on the white of
the egg when you remove the shell. Keep the messages short and
have a ball.
It’s the stuff that made Tom’s mouth pucker up so that he had to suck Jerry up through a straw!
Seriously, it’s a chemical used as (among other things) a preservative in pickling. Supposedly, you can find it in the spice section of a grocery store. If that doesn’t work, it’s also what those “Thai deoderant crystals” are made of.
Chemically, it’s potassium aluminium sulphate dodecahydrate, KAl(SO[sub]4[/sub])[sub]2[/sub].12H[sub]2[/sub]O. The water is “water of crystallisation” and can be boiled off (that’s not uncommon; copper sulphate’s another common example). I have a styptic pencil that I sometimes use for shaving cuts; that’s basically a stick of alum.
I second the recommendation to look in the spice aisle of your grocery store. McCormick sells it in small squat plastic jars of 1.9 ounces. I pay $3 or $4.
“Happy Easter, what is alum? / Potassium aluminum sulphate” actually works to the tune of “Christ the Lord is risen today”, though the stresses are in weird places in the chemical name.
Every year I lipstick RedruM on my door. Parents get a kick out of it. But this isn’t why I came back…
The guy who told me the egg trick is a Vietnam veteran. He said the prostitutes over there used gobs of the stuff in themselves with bowls of it next to their beds. He thinks it was for tightening. I don’t know.