It is not often in this country that we have the mystery of the concealed identity in the criminal dock. No advocate rises at the Old Bailey and endeavours to influence a jury by hinting that the prisoner on trial for his life is the son of some great personage. "If you knew who I was," exclaimed Prado, "you would be astounded," and his advocate repeated his words. We have no guilty wretches posing in the dock and pretending that by their silence they are screening a name which is dearer to them than life. Something of that kind was, it is true, attempted by Mrs. Pearcy (Mary Eleanor Wheeler), the murderess of Mrs. Hogg and her child, who arranged that after her death an advertisement should be inserted in all the principal Madrid papers. The advertisement duly appeared: "M. E. C. P. Last wish of M. E. W. Have not betrayed." The story of the murder of Mrs. Hogg was only half told. Mrs. Pearcy practically acknowledged her guilt when she said that her sentence was just; but there was always an unfathomed mystery in the case which was intensified by the last request of the woman on the brink of eternity, that someone in a foreign land should be notified that she had "not betrayed." Yet innocent persons have suffered for others and have not betrayed. An innocent man has stood in the shadow of the scaffold and refused to say the words which would have cleared him, because they would have imperilled the life of one whom he was determined not to betray. Innocent men and innocent women have confessed to crimes and paid the penalty. The story told by the French novelist of the man in the last stage of consumption who confessed to a murder by arrangement with the relatives of the real murderer has its counterpart in fact. The man, who proved that truth is stranger than fiction, feared a public trial. He committed suicide, and left a confession behind him which tallied with all the ascertained facts. His confession could well bear the impress of truth, for the details were communicated to him by the actual author of the crime. The man took the eternal shame upon himself for a sum of money assured to those who, had he died of the disease that must soon have been fatal, would have been left in the direst poverty. It was not until some years after the suicide of the supposed murderer that suspicion was aroused as to the genuineness of the confession by certain circumstances which came accidentally to the knowledge of a retired police-officer. And then it was useless to move further in the matter. To obtain the conviction of another man would, in the circumstances, have been almost impossible. In the old days physical torture wrung a false confession of guilt from hundreds of men and women. To-day it is mental torture that now and again causes an innocent person to plead guilty to crimes that can be purged with imprisonment, but more frequently there is a solid and substantial benefit as the temptation.