It was the glass harmonica, invented by Benjamin Franklin. Donizetti scored the mad scene in "Lucia di Lamermoor" for the glass harmonica, not for the flute. However the glass harmonica players got the shakes, went mad and died. 

It was believed that it was the transcendental beauty of the music that killed them. It was lead poisoning picked up from the glass by the wet fingers. Or was it? I was told way back in Devonian times that it was.