Old Fashioned Lemon Pie

6 eggs, separated into yolks and whites
½ cup butter
2 ½ cup sugar
juice of 2 lemons
grated rind of 1 lemon
pinch of salt
unbaked pie shell

Cream butter and sugar.  Add beaten egg yolks, lemon juice and rind, salt.  Beat egg whites until stiff and fold into mixture.  Pour into pie shell and bake for 30 minutes at 350 degrees.