Chocolate sponge

Chop 3oz. of good chocolate into small pieces, put into a saucepan with 2 tablespoonfuls of water; stir until melted; add a little essence of vanilla; let this cool. Beat the white of 4 eggs to a stiff froth, then whisk the chocolate in lightly. Heap this up roughly on a glass dish. Cut about half the contents of a tin of pineapple into neat squares, border the chocolate sponge with pineapple, and serve at once.