Wash the fruit, cut in half and squeeze out the juice. Remove some of the pith if it is thick, cut it up coarsely and put it with the pips in a muslin bag. Slice the peel finely. Put all the fruit and juice into a bowl, cover with the water and leave overnight. Next day put it all into a preserving-pan and cook gently for 2 hr. or until the peel is soft. Remove the bag of pips, add the sugar, stir until it is dissolved, then boil rapidly until setting point is reached. Pot and cover in the usual way.