The common purpose of the statutes is to restrict the rule compelling disclosures so as to protect communications with a physician in his professional capacity; but the limit to which the protection is extended differs in the various States. An analytic comparison of the statutes tends to show how far the interpretation of one is useful in construing another. _I. Nature of the Exclusion._—In California, Idaho, Minnesota, Montana, North Dakota, Oregon, South Dakota, Utah, and Washington the statutes apply only to testimony in civil actions.[223] The other statutes make no distinction between civil and criminal proceedings. The active words are of course different in the several statutes, but they indicate a purpose to extend a privilege that the person entitled to it may insist upon maintaining, with the single exception of the law of North Carolina, which provides that the presiding judge of a superior court may compel a disclosure, if in his opinion the same is necessary to a proper administration of justice. Some of the statutes show clearly that it is the patient’s privilege, and suffer the patient or his representatives to waive it, either expressly or by conduct which the law declares to amount to a waiver.[224] Others are silent on this subject. In California, Colorado, Idaho, Iowa, Minnesota, Montana, Nebraska, Nevada, New York, North Dakota, Ohio, Oregon, South Dakota, Utah, Washington, and Wyoming, it is expressly provided that the patient’s consent is necessary before a disclosure will be permitted. In Colorado, Kansas, Oklahoma, and Oregon, if the patient offer himself or a physician or surgeon as a witness, that is to be deemed a consent. In Nevada, in any suit or prosecution for malpractice, if the patient or party suing or prosecuting shall require or give consent, and any physician or surgeon shall give testimony, then the defendant may call any other physicians or surgeons as witnesses without the consent of the patient or party suing or prosecuting. In Ohio and Wyoming, if the patient voluntarily testify the physician may be compelled to testify on the same subject. _II. The Witness._—In Indiana, Ohio, and Wyoming the privileged witness is termed a _physician_; in the other States and Territories, the privilege extends to a _physician_ or _surgeon_.