Glass delusion is an external manifestation of a psychiatric disorder recorded in Europe mainly in the late Middle Ages and early modern period (15th to 17th centuries). People feared that they were made of glass "and therefore likely to shatter into pieces".

In the 16th and 17th centuries of Europe, glass became a valuable commodity. It was regarded as a magical, alchemical object. Associated with fragility and luxury, glass influenced the way noblemen of early Europe perceived their esteemed positions in society. This fixation on a novel material contributed to the manifestation of the delusion. Concentration of the glass delusion among the wealthy and educated classes allowed modern scholars to associate it with a wider and better described disorder of melancholy.

source: Wikipedia

Peter Clatworthy
4 years ago

She [Ella Fitzgerald] did this ad when I was working as a Marketing Manager for Memorex.  She used to phone and say, "Hi Pete, it's Mrs Memorex here".  We were challenged to break a glass live on German television because the television station had run a news item stating that the ad was a cheap trick, even though we always stated in the voice over "the amplified voice of Ella Fitzgerald".

Well, I had to obtain a glass that would resonate at the same frequency as Ella's voice.  It took several weeks and eventually we got 3 glasses specially manufactured by a company in France.

Without rehearsal she appeared on the show.  The glass was placed in a sound box similar to the one shown in the ad.  She sang "oobe do be do be do'oooooo!" and held the last note ... until the glass busted!  She repeated the experiment, busting the remaining 2 glasses.

I had the good sense to collect and keep the shattered pieces in plastic bags.  When I got back to the UK I sent the pieces to a friend of mine and he reconstructed and encapsulated them in acrylic blocks.  We etched MEMOREX on to the blocks so that they could be used as desk paperweights.  I gave one to the President of Memorex, one to the Country Manager of Memorex UK and I still have one, the first glass she broke.  It is on my desk as I type this post.

After the programme Ella came for dinner at a small local restaurant in Frankfurt.  There was a piano in the corner of the restaurant where a little old man was playing for the customers.  Between courses she went over to the pianist and chatted away for a few minutes.  Obviously he was thrilled to meet her.  At the end of our meal she asked "Would you like me to sing a song for you?"  Is the Pope a Catholic?  She had obviously warned the old man and to a virtually empty restaurant, but just for me, she sang "A Tisket a Tasket".  I fell in love there and then!  What a lovely lady and great memories.

above; copy of Miguel de Cervantes' novella
The Glass Lawyer, 1613