A somewhat different question has arisen in the case of a witness who, like a family physician or attending physician, has learned facts and has been paid for his attendance, or who exacts payment for his attendance, as a physician from his patient, and this question is; when such a professional man has been called upon to testify to the information he thus attained, whether he can be asked for, and required to give, opinions based on those facts? Necessarily, having learned the facts by observation, such as the appearance, symptoms, and actions of the patient, he is, when testifying as to these matters, nothing more or less than an ordinary witness, because he is testifying to matters of observation. As to these matters public policy requires, except so far as it has been modified, or rather extended, by our statutes which forbid testimony as to privileged communications, that he must testify, the same as any other witness. But suppose that, having so testified to the facts, he is asked to give his opinion; for example, in an insanity case, whether the symptoms that he found in his patient led him to the belief as a professional man of experience and skill that his patient was sane or insane. The question is, Can he be compelled to give that opinion, if he chooses to decline to give it without the promise or assurance of further compensation than the mere _per diem_ fee and mileage of an ordinary witness? The best authority is to the effect that he must so testify, the reasoning of the court being that his opinion is only a part of what he derived from his original relation of physician to his patient. Wright _v._ The People, 112 Ill., 540; same case, 33 Alb. L. J., 79. _Same Rule in Civil and Criminal Cases._—The rule is the same whether the professional man is called to testify as an expert in civil or criminal cases. In either one he is not obliged to give an opinion as such, independent of a personal knowledge of the facts in the case, without being paid or assured reasonable compensation therefor. His proper course of conduct is, when he has obeyed the subpœna and is in the presence of the court and has been sworn, and the questions put by counsel disclose that the object of his examination is to elicit from him an opinion, to state to the court that he has not been paid any other compensation than that of an ordinary witness, and that he respectfully declines to give an opinion in the case as an expert, without compensation proportionate to the value of his opinion.[182]