GUIIEAU S CASE. ���167 ���always been entirely satisfactory or in harmony with the conclusions of medical science. Courts iiave, in former times, undertaken to lay Jown a law of insanity without reference to aiid in ignorance of the medical aspects of the subject, wlieu it could only be properly dealt with tlirough a concurrent and harmonious treatment by the two sciences of law and medicine. They have, therefore, adopted and again discarded one theory after another in the effort to find some common ground where a due regard for the security of society and humanity for the afflicted may meet. It will be my effort to give you the results most commonly accepted by the courts. �It may be well to say a word as to the evidence by which courts and juries are guided in this diffieult and delicate inquiry. �That subtle esscDce which we call "mind" defies, of course, ocular inspection. It can only be known by its outward manifestations, and they are found in the language and eonduct of the man. By these his thoughts and emotions are read, and according as they conform to the praotice of people of sound mind, who form the large majority of mankind, or contrast harshly with it, we form our judgment as to his Boundnesg of mind. For this reason evidence is admissible to show eonduct and language at different times and on different occa- sions> which indicate to the general mind some morbid condition of the intellectual powers ; and the more extended the view of the per- son's life the safer is the judgment formed of him. Everything re- lating to his physical and mental history is relevant, because any conclusion as to his sanity must often rest upon a large number of facts. As a part of the language and eonduct, letters spontaneously written afford one of the best indications of mental condition. �Evidence as to insanity in the parents and immediate relatives is also pertinent. It is never allowed to infer insanity in the aceused from the mere fact of its existence in the ancestors. But when tes- timony is given directly tending to prove insane eonduct on the part of the aceused, this kind of proof is admissible as corroborative of the other. And therefore it is that the defence have been allowed to introduce evidence to you covering the wbole life cf the aceused, and reaching to his family antecedents. �In a case so full of detail as this I shall deem it my duty to you to assist you in weighing the evidence by calling your attention to par- ticular parts of it. But I wish you distinctly to understand that it is your province, and not mine, to decide upon the facts ; and if I, at any time, seem to express or intimate an opinion on them, which I ��� �
