SEC. 14. And be it further enacted, That all the before-mentioned courts of the United States, shall have power to issue writs of scire facias, habeas corpus, and all other writs not specially provided for by statute, which may be necessary for the exercise of their respective jurisdictions, and agreeable to the principles and usages of law. And that either of the justices of the supreme court, as well as judges of the district courts, shall have power to grant writs of habeas corpus for the purpose of an inquiry into the cause of commitment.Provided, That writs of habeas corpus shall in no case extend to prisoners in gaol, unless where they are in custody, under or by colour of the authority of the United States, or are committed for trial before some court of the same, or are necessary to be brought into court to testify.
