“ But he cannot be compelled to waive the objection if he chooses seasonably to insist upon it, and any rule of court which seeks to compel a waiver is unauthorized by law and invalid. So it has been held that, under the act which requires the practice in the courts of the United States to conform as near as may be to the practice of the courts of the states in which they are held, state statutes which give a special appearance to challenge the jurisdiction the force and effect of a general appearance must not be followed by the courts of the United States. ”

“ As this suit was brought after the passage of the amending act, it was brought in the only district where it could be maintained, if the amending act were retrospective. But it is not retrospective. United States Fidelity & G. Co. ”