A witness may be subjected to _three_ examinations: first, by the party on whose side he is engaged, which is called the 'examination in chief,' and in which he affords the basis for the next examination or 'cross-examination' by the opposite side. The third is the 're-examination' by his own side. In the first he merely gives a clear statement of facts or of his opinions. In the next his testimony is subjected to rigid examination in order to weaken his previous statements. In the third he is allowed to clear up any discrepancies in the cross-examination, but he must not introduce any new matter which would render him liable to another cross-examination. The medical witness should answer questions put to him as clearly and as concisely as possible. He should make his statements in plain and simple language, avoiding as much as possible technical terms and figurative expressions, and should not quote authorities in support of his opinions. An expert witness when giving evidence may refer to notes for the purpose of refreshing his memory, but only if the notes were taken by him at the time when the observations were made, or as soon after as practicable. There are various _courts_ in which a medical witness may be called on to give evidence: 1. =The Coroner's Court.=--When a coroner is informed that the dead body of a person is lying within his jurisdiction, and that there is reasonable cause to suspect that such person died either a violent or unnatural death, or died a sudden death of which the cause is unknown, he must summon a jury of not less than twelve men to investigate the matter--in other words, hold an inquest--and if the deceased had received medical treatment, the coroner may summon the medical attendant to give evidence. By the Coroners (Emergency Provisions) Act of 1917, the number of the jury has been cut down to a minimum of seven and a maximum of eleven men. By the Juries Act of 1918, the coroner has the power of holding a court without a jury if, in his discretion, it appears to be unnecessary. In charges of murder, manslaughter, deaths of prisoners in prison, inmates of asylums or inebriates' homes, or of infants in nursing homes, he must summon a jury. The coroner may be satisfied with the evidence as to the cause of a person's death, and may dispense with an inquest and grant a burial certificate. Cases are notified to the coroner by the police, parish officer, any medical practitioner, registrar of deaths, or by any private individual. Witnesses, having been cited to appear, are examined on oath by the coroner, who must, in criminal cases at least, take down the evidence in writing. This is then read over to each witness, who signs it, and this forms his _deposition_. At the end of each case the coroner sums up, and the jury return their verdict or _inquisition_, either unanimously or by a majority.