Heat 3 cups milk in top part of double boiler over hot water.
Mix cornmeal with salt and remaining milk.
Add to hot milk; cook, stirring, until thick; cover and cook for about 5 minutes.
Add corn and cook for a few minutes longer.
Add butter and stir until melted.
Fold in eggs.
Put in greased 2-quart casserole.
Bake in preheated moderate oven (375° F.) for 1 hour, or until firm but light.
Serve at once with lots of butter. (Spoon bread will sink when removed from oven.)