The recent trials for murder, in which insanity has been alleged for the defence, whatever differences of opinion they may have given rise to, have clearly shown how entirely unfitted a common jury is to decide the delicate and difficult question of a prisoner's mental state. Had the wit of man been employed to devise a tribunal more unfitted for such a purpose, it might have exhausted itself in the vain attempt. It is one of the anomalies of British jurisprudence that while in an action for libel or any civil injury a special jury may be claimed, and the services of men who are above the lowest levels of ignorance and prejudice be thus obtained, it is quite otherwise when a person is on trial for his life. In this most momentous issue, however complicated the circumstances, however obscure the facts, he must stand the verdict of twelve common jurymen. In ordinary cases of murder, when the facts are such as any person of average sense and experience may judge of, the system works sufficiently well, or at any rate no great harm ensues; but in any case in which it is necessary to form a judgment upon scientific data, a common jury is assuredly a singularly incompetent tribunal. The very terms of science they are ignorant of, and they either accept the data blindly on the authority of a skilled witness, or reject them blindly from the prejudice of ignorance. The former result is commonly what happens in regard to scientific evidence of poisoning; the latter is commonly what happens in regard to scientific evidence of insanity. There are few persons who, without having had a special chemical training, would venture to give an opinion on the value of the chemical evidence given in a case of poisoning, but everybody thinks himself competent to say when a man is mad; and as the common opinion as to an insane person is that he is either a raging maniac or an idiot, it is no wonder that juries are prone to reject the theory of insanity which is propounded to them by medical men acquainted with its manifold varieties. It would seem to be an elementary principle of justice that a prisoner on trial for his life should have the right to claim a jury of men specially competent, or at any rate not absolutely incompetent, to judge of the facts on which his defence is to be based.