We are told that "all the world loves a lover," and it is, perhaps, equally true that most people like to read the details of clever detective exploits. The deeds of criminals naturally awaken the emotions of horror, fear, curiosity and awe in proportion to their heinousness and the mystery by which they are enveloped. Consequently the detective officer who pierces the mystery--unravels it thread by thread, and by unerring sagacity penetrates its innermost depths and lays his hand on the criminal--is at once invested, in the popular mind, with qualities approaching the preternatural. The vivid and fertile imagination of the literary romancist magnifies the illusion. The detective of the successful novel resembles the Deity in his attributes of ubiquity and omniscience. In whatever city his functions are exercised we may be sure that he knows every man-Jack of the criminal classes, their past and present history, their occupation and their residence. He knows all their names, their aliases and their soubriquets, just as Julius Cæsar, as tradition tells, knew all the soldiers of his army. Moreover, they are invariably individuals of remarkable personality. While endowed with a strong spice of the world, the flesh and the devil, they are at the same time clothed in a sort of white robe of social immaculacy. They are half lamb and half wolf, if such a paradoxical being were possible. Take, for instance, the Inspector Javert of Victor Hugo: A tall man, dressed in an iron-grey great coat, armed with a thick cane, and wearing a hat with a turndown brim; grave with an almost menacing gravity, with a trick of folding his arms, shaking his head and raising his upper lip with the lower as high as his nose, in a sort of significant grimace. He had a stub nose with two enormous nostrils, toward which enormous whiskers mounted on his cheeks. His forehead could not be seen, for it was hidden by his hat; his eyes could not be seen because they were lost under his eyebrows; his chin was plunged into his cravat; his hands were covered by his cuffs, and his cane was carried under his coat. But when the opportunity arrived there could be seen suddenly emerging from all this shadow, as from an ambush, an angular, narrow forehead, a fatal glance, a menacing chin, an enormous hand, and a monstrous rattan. When he laughed, which was rare and terrible, his thin lips parted and displayed not only his teeth but his gums, and a savage, flat curl formed round his nose. When serious he was a bulldog, when he laughed he was a tiger. His guiding principles--or perhaps instincts is the more appropriate word--were respect for authority and hatred of rebellion. In his eyes all crimes were only forms of rebellion. Give a human face, writes Hugo, to the dog-son of a she-wolf and we shall have Javert. No wonder that his glance was a gimlet, or that his whole life was divided between watching and overlooking. And, as if all this analytic