Mix a quarter of a pound of sifted flour in a small basin, with half a pint of lukewarm water, to which three-quarters of an ounce of fresh butter has been added. Place in a saucepan, which should be tilted on the range so that when the water boils the butter can be skimmed off the top. Add, if necessary, a little more water to make a soft paste, beating well with a spatula, to keep it free from lumps, and of a proper consistence ; it must be gray and compact-looking. Add just a little warm water to render the paste soft and diluted, although sufficiently thick to cover the objects for which it is intended;that means, it must drop easily from the spoon. Add to this half a pinch of salt and two egg-whites ; beat well together for one minute, and use at once.