The physician is always allowed discretionary powers over the patient entrusted to his care in modes of treatment, so as to be able to alter them according to the varying necessities of the case. Unless such change of treatment involves a risk of life or consequences of which he is unwilling to assume the responsibility, he is not under obligation to give notice or obtain permission before making it. Particularly is this the case where the patient is not at home or among friends or relatives, but is in some degree in his custody and under his exclusive supervision, as well as care. In such circumstances he is authorised to perform operations, or change his treatment, or enforce discipline essential to its fulfilment, without first consulting or obtaining permission from friends or guardians at a distance, since delay might involve a greater risk to the health |26| and possibly the life of the patient than would a necessitated operation; and of such things he alone is the proper, as he alone can be the best, judge. He may recover his fees for such operation or change of treatment without proving that it was necessary or proper, or that before he performed it he gave notice to the party who had to pay, or that it would have been dangerous to have waited until such notice had been given. The burden of proving unskilfulness or carelessness in the operation lies upon the party objecting to it [47]. When a medical man is called as a witness before a court, to testify as to facts within his knowledge, he must attend and give evidence upon payment of the same fees as other witnesses are entitled to; unless it is otherwise provided by statute. Where a statute provides that a medical man should be paid a certain witness fee, he is entitled to that fee although he be not called to give professional evidence, and it is not necessary to prove that he is in practice [48]. A witness should be paid his fees when he is subpœnaed; but even if he attends he can refuse to give evidence until he is paid, unless he takes the oath before making the objection [49]. A subpœna should be served a reasonable time before the trial, to enable a witness to put his affairs in such order that his attendance on the court may be as little detrimental as possible to his interests [50]. Where a medical man is summoned to attend a coroner’s inquest, unless the statute law is clearly to the contrary, |27| he is only entitled to be paid for each days attendance, not for each body on which the inquest was held [51].