Over on the Dear Dogberry page, a reader has asked why we have the phrase walking on eggshells when walking on eggs would make much more sense. For myself, I can't understand why you would do either. However, upon investigation I've discovered that walking on eggs was the original version of the phrase. The OED records it from 1734, where as the walking on eggshell doesn't pop up until 1860.
A much more amusing variant is a thing called an egg dance, which can be performed at home, but probably not on your best carpet. All you'll need is a bunch of eggs, which you arrange on the floor, and a blindfold, which you put over your eyes. You now dance around trying not to tread upon any eggs however lightly.
Egg dancing gets a mention in a sixteenth century play called The Longer Thou Livest, The More Fool Thou Art.
Upon my one foot prettily can I hop
And dance it trimly about an egg.
And there's a good description of it from 1801:
This performance was common enough about thirty years back, and was well received at Sadler's Wells; where I saw it exhibited, not by simply hopping round a single egg, but in a manner that much increased the difficulty. A number of eggs, I do not precisely recollect how many, but I believe about twelve or fourteen, were placed at certain distances marked upon the stage; the dancer taking his stand, was blind-folded, and a hornpipe being played in the orchestra, he went through all the paces and figures of the dance, passing backwards and forwards between the eggs without touching one of them.
As you can imagine, an egg-dance became a byword for any intricate and difficult task, and makes a lot more sense than walking on either eggs or eggshells.
Scrambled eggs at the Inky Fool offices
P.S. The first part of the Etymologicon was read out by Hugh Dennis on Radio 4 this morning. You can listen to it by following this link.