For me the strange story dates back to that autumn day when my uncle Dorgeroux appeared, staggering and unhinged, in the doorway of the room which I occupied in his house, Haut-Meudon Lodge. None of us had set eyes on him for a week. A prey to that nervous exasperation into which the final test of any of his inventions invariably threw him, he was living among his furnaces and retorts, keeping every door shut, sleeping on a sofa, eating nothing but fruit and bread. And suddenly he stood before me, livid, wild-eyed, stammering, emaciated, as though he had lately recovered from a long and dangerous illness.