found not lunatic by a jury legally constituted to enquire into the state of his mind, would be the strongest bar to a plea of insanity in a criminal court, who after such proceedings would be little disposed to credit the theories of medical metaphysicians. It is not necessary to enter on an investigation, or to enumerate all the particular states of mind which may be comprehended under the terms Insanity, Madness or Lunacy, but it is a subject of grave and important enquiry to ascertain what degree of mental derangement, or imbecility ought to disqualify an individual from being the master of his person and property. It has sometimes occurred that persons evidently under mental derangement have for months continued to transact their affairs with prudence, and have conducted themselves quietly in society. Notwithstanding the disordered state of their ideas, they have not obeyed the impulse, nor followed the direction of their insane opinions, and have forborn to act to their own detriment or to the annoyance of others. Several of such instances have fallen under my own observation: but the greater part have eventually destroyed themselves, or become so furious that seclusion was absolutely necessary. It is therefore impossible, under a state of existing insanity to predict the future conduct of an individual thus affected, or to become responsible for the continuance of his harmless disposition. In the discussion of this question it should be kept in view that the medical evidence is called upon to state, in the first place, that the person is of insane mind: and secondly, that in consequence of such state, he is incapable of conducting himself or of managing his affairs. If it be a matter of general and legitimate inference, that a person of insane mind is consequently unable to the management of himself and affairs; the proof of his insanity necessarily involves his incompetency: if it be supposed that, although of insane mind, a man may be capable of conducting himself and his affairs, it is then incumbent on the medical practitioner to shew from the nature and tendency of his particular insanity that he is unfit to be trusted with either. Such prediction must necessarily be the result of copious experience, and formed in the way of a general conclusion, and it should be understood that this opinion of his incompetency regards his existing condition of mind at the time of the legal enquiry. Although a person might labour under a variety of mental infirmities, which by medical practitioners might be technically denominated false perception, delusion, hallucination, &c. still if these symptoms did not go to the extent of disqualifying him from conducting himself and managing his affairs, such symptoms in a legal point of view would, probably, not amount to insanity, nor justify the restraint of a commission of lunacy. It is true such symptoms seldom occur without producing the incompetency which the law regards as the warrant for its