The following sheets are addressed to the readers of different pursuits, law and medicine:—from the latter, I have heretofore experienced much indulgence and encouragement, when the result of my professional labours has been submitted to their judgment:[i:A]—to the former I am little known: and here feel it necessary, by a distinct avowal, to assert that I have in no manner presumed to encroach on their province. Although the title may seem to imply an incorporation of the two sciences, yet it is not to be considered as the combination of definite proportions of legal and medical knowledge. It has been modestly conceived that the general phenomena of disordered intellect, and the criteria of insanity, would not be unacceptable to the advocate; who might thereby become enabled to adapt the facts in nature to the scale of justice. Furnished with such information, he will be instructed to institute appropriate enquiries for the discovery of truth, and to ascertain what is the duty of the medical evidence to supply:—so that he may not be pressed beyond his resources, nor the depths of his intelligence be left unsounded. On the practitioner of my own profession I have ventured to impress the importance and moral obligation of his evidence before the tribunal of justice, and to enforce, that the value of medical opinion becomes enhanced by perspicuity of conveyance, and derives authority from the exposure of its foundations. It has likewise been my object, to direct his attention to those leading points which usually constitute the subjects of his deposition, or are presented for his solution during the course of legal examination. [i:A] Vide Observations on Insanity, 8vo, 1798.—Observations on Madness and Melancholy, 8vo, 1809.—Illustrations of Madness, 8vo, 1810.—Considerations on the Moral Management of the Insane, 8vo, 1817. The technical language of the learned professions is commonly inveloped in mysterious obscurity:—persons for the most part acquire names without investigating their force and legitimate import; and currently employ them rather from habit than comprehension: it has therefore been my anxious endeavour to scrutinize words of important meaning; and to convey the manifestations of mind and the symptoms of disease, by expressions generally understood, and emancipated from the thraldom of professional nomenclature.