Slit the corn kernels in two and grate from the cobs. Put the cobs into the boiling water and let them boil slowly about an hour, till the water is reduced to three quarts. Then take the cobs out and drain over the kettle. Add the Corn and let boil until soft. This will require about thirty minutes. Take the Soup off and press all through a sieve. Season highly and set back to simmer gently, adding, in the meanwhile, the flour and butter, thoroughly rubbed together. Stir constantly till the Soup thickens, and then add the boiling milk. Cook a moment only, take off the fire, stir in the beaten yolks and serve hot, with buttered toast cut in dice shape.