In Bailey v. Alabama, 211 U.S. 452 (1908), reviewing a judgment of the Supreme Court of Alabama which affirmed a judgment of a lower court denying a discharge on habeas corpus to the plaintiff in error, we said (p. 453): "If the Supreme Court had affirmed the denial of the discharge on the ground that the proper course was to raise the objections ruled upon at the trial of the principal case on the merits and to take the question up by writ of error, it would have adopted the rule that prevails in this court and there would be nothing to be said."