In considering the use of legal knowledge as applicable to private practice, _Sir William Blackstone_ has mentioned one of many instances; it would be useful if the medical attendant were acquainted with at least the formal part of executing wills; in the moment of danger and distress, when all around the bed of death are confused with fear, or overwhelmed in affliction, the physician, probably a confidential friend, whose duty and habit ensures self-possession, may be the only person competent to advise. How many estates have been lost to the intended heir, by the want of a third witness to a devise of real property? or by an attestation informally signed, because the curtains of the bed were drawn, and the testator could not see the witnesses? From considering the last, let us turn back and enquire whether medical observation may not be necessary in the first scene of life. A midwife, unacquainted with the law of tenant by the courtesey, will scarcely note whether a child, certainly dead within a minute of its birth, did in that period move a limb or open an eye; he will not consider whether a momentary quivering of the lip was a sign of independent vitality, or the expiring remains of uterine life. If after a lapse of ten or twenty years he should be examined in a court of justice on this point in order to determine the right of the father to his estate for life, he will be unable to satisfy his own conscience, or the ends of justice; but once acquainted with the importance of these observations, he will never fail to note the occurrence, whenever he has reason to believe that the circumstances of the case may give rise to legal question. In cases of impotence, sterility, idiotcy, and lunacy, the confidential medical attendant is the first person consulted on the subject; how often may he refute a groundless accusation, remove a causeless fear, and prevent a public exposure, by forming and demonstrating correct views of the subject? how often too may he aid the oppressed, defeat the guilty, and protect the innocent, by a knowledge of the legal remedies against fraud or coercion? In many criminal cases too the surgeon is of necessity among the first witnesses of the deed; is it not important that he should know what evidence will be required to prove its perpetration? surrounded by ignorant or prejudiced persons, his calm and accurate view, not only of medical, but of general points, becomes of peculiar importance; yet if he be unacquainted with the forms of judicial enquiry, unversed in the history of criminal courts, he will be as little able to direct his attention to the proper objects, or to divest his mind of undue bias, as the most ignorant of the by-standers.