The testimony of a wit- ness reduced to writing, in due form of law, by virtue of a commission or other author- ity of a competent tribunal, or according to the provisions of some statute law, to be used on the trial of some question of fact in a court of justice. 8 Blatchf. 456; 23 N. J. L. 49. Depositions were not formerly admitted in common-law courts, and were afterwards admitted from necessity, where the oral testimony of a witness could not be ob- tained. But in courts of chancery this is generally the only testimony which is taken; Ad. Eq. 363. In some of the United States, however, both oral testimony and deposi- tions are used, the same as in courts of common law. In criminal cases, in the United States, de- positions cannot be used without the con- sent of the defendant; 3 Greenl. Ev. § 11; 15 Miss. 475; 4 Ga. 335. The constitution of the United States pro- vides that in all criminal prosecutions "the accused shall enjoy the right to be con- fronted with the witnesses against him." Amend. art. 6. This principle is recognized in the constitutions or statutes of most of the states of the Union. 3 Greenl. Ev. §-11; Cooley, Const. Lim. 887. In some of the states, provision is made for the taking of depositions by the accused. Conn. Comp. Stat. art. 6, § 162; 3 Greenl. Εν. § 11. Provision has been made for taking de. positions to be used in civil cases, by an act of congress and by statute in most of the states. The Rev. Stat. §§ 863-876, directs that when, in any civil cause depending in any district in any court of the United States, the testimony of any person shall be necessary who shall live at a a greater distance from the place of trial than one hundred miles, or is bound on a voyage to sea, or is about to go out of the United States, or out of such district, and to a greater distance from the place of trial than as aforesaid, before the time of trial, or is ancient, or very infirm, the deposition of such person may be taken, de bene esse, before any justice or judge of any of the courts of the United States, or any com- missioner of a circuit court, or any clerk of a district or circuit court, or before any chancellor, justice, or judge of a supreme or superior court, mayor or chief magistrate of a city, or judge of a county court or court of common pleas of any of the United States, or any notary public, not being of counsel or attorney to either of the parties, or interested in the event of the cause; provided that a notification in writing from the party or his attorney, to the ad- vense party, to be present at the taking of the same, and to put interrogatories, if he think fit, be first made out and served on the adverse party, or his attorney, as either may be nearest. And in all cases in rem, the person having the agency or possession of the property at the time of the seizure shall be deemed the adverse party until a claim shall have been put in; and whenever, by reason of the absence from the district, and want of an attorney of record, or other reason, the giving of the notice herein re- quired shall be impracticable, it shall be lawful to take such depositions as there shall be urgent ne- cessity for taking, upon such notice, as any judge authorized to hold courts in such circuit or district shall think reasonable and direct. Any person may be compelled to appear and depose, as provided by this section, in the same manner as witnesses may be compelled to appear and testify in court. And every person deposing as aforesaid shall be care- fully examined and cautioned, and sworn or affirmed to testify to the whole truth, and shall subscribe the testimony by him or her given, after the same shall be reduced to writing, which shall be done only by the magistrate taking the deposition, or by the de- ponent in his presence. And the depositions so tak- en shall be retained by such magistrate until he de- liver the same with his own hand into the court for which they are taken, or shall, together with a cer- tificate of the reasons as aforesaid of their being taken, and of the notice, if any given, to the adverse party, be by him the said magistrate sealed up and directed to such court, and remain under his seal until opened in court. But unless it appears to the satisfaction of the court that the witness is then dead or gone out of the United States, or to a great- er distance than one hundred miles from the place where the court is sitting, or that, by reason of age, sickness, bodily infirmity, or imprisonment, he is unable to travel and appear at court, such deposi- tion shall not be used in the cause. Provided that nothing herein shall be construed to prevent any court of the United States from granting a dedimus potestatem, to take depositions according to com- mon usage, when it may be necessary to prevent a failure or delay of justice, which power they shall severally possess; nor to extend to depositions tak- en in perpetuam rei memoriam, which, if they relate to matters that may be cog