Blend milk into cream cheese and salt in a heavy saucepan.
Stir over low heat until mixture is creamy and smooth.
Set aside to cool.
Toss bread cubes, parsley, onion, and rosemary together in a large bowl.
Add cream cheese mixture; toss lightly and thoroughly.
Blend in the beaten egg yolks.
Beat egg whites until stiff, not dry, peaks are formed.
Fold gently into cheese-bread mixture until thoroughly blended.
Turn into an ungreased 1 1/2-quart souffle dish (deep casserole with straight sides).
Dot top with small portions of butter (about 12 pieces).
Set dish in a pan in a 350°F oven.
Pour boiling water into pan to a depth of 1 inch.
Bake about 1 hour, or until a knife inserted halfway between center and edge comes out clean.