But the fact that it is the duty of a physician to prescribe for a person in case of need, does not constitute the relation, though the position of the physician gives him the opportunity to observe such person; so, therefore, a jail physician was not precluded from testifying as to what he had observed of a prisoner, where it did not appear that he had ever attended the latter in a professional capacity or had ever been called on to attend him.[393] It would seem, however, that where it is the duty of a physician to attend a person in a professional capacity or to acquire knowledge concerning him in such capacity, he cannot disclose information actually acquired in the performance of his duty. It has been said that a medical attendant at an insane asylum cannot testify as to the mental condition of an inmate;[394] and that a physician employed in a hospital to notice and enter in its records the arrival and condition of the patients coming in, cannot testify as to information so acquired.[395] It is immaterial that another person employs the physician to examine the patient, and to report to the employer, and that the person examined does not appear to desire any knowledge as to his condition; if the examination is made as a professional act, the relation of physician and patient is established between the physician and the person examined, even though it be the only interview.[396] And in a case where the public prosecutor sent a physician to a person for the purpose of making a professional examination, so as to obtain evidence against another person charged with crime, and the person examined accepted the services of the physician in a professional character, it was held that he could not testify as to the results of his examination.[397] But where the district attorney sent a physician to jail to make an examination of a prisoner’s mental and physical condition, and he made such examination, and it did not appear that he prescribed for or treated the prisoner or that the prisoner accepted his services, the opinion of the physician as to his mental condition was admitted.[398]