But the Frenchman with the gold glasses and the big amethyst ring upon his finger merely laughed, and refused to satisfy me. From him, however, I learned that the depredations of the formidable gang had been unequalled in the annals of crime. Many of the greatest jewel robberies in the European capitals in recent years had, it was now proved, been effected by them, as well as the theft of the Marchioness of Mottisfont's jewels at Victoria Station, which were valued at eighteen thousand pounds, and were never recovered; the breaking open of the safe of Levi & Andrews, the well-known diamond-merchants of Hatton Garden, and the theft of a whole vanload of furs before a shop in New Bond Street, all of which are, no doubt, fresh within the memory of the reader of the daily newspapers. Every single member of that remarkable association of thieves was an expert in his or her branch of dishonesty, while the common fund was a large one, hence members could disguise themselves as wealthy persons, if need be. One, when arrested, was found occupying a fine old castle in the Tyrol, he told me; another--an expert burglar--was a doctor in good practice at Hampstead; another kept a fine jeweller's shop in Marseilles, while another, a lady, lived in style in a great chateau near Nevers. "And who exposed them?" I asked, much interested. "Somebody must have betrayed them." "Somebody did betray them--by anonymous letters to the police--letters which were received at intervals at the Prefecture in Paris, and led to the arrest of one after another of the chief members of the gang. It seemed to have been done by some one irritated by Bell's arrest. But the identity of the informant has never been ascertained. He deemed it best to remain hidden--for obvious reasons," laughed my friend at my side. "You seem to know a good many facts regarding the affair," I said. "Have you no idea of the identity of the mysterious informant?" "Well"--he hesitated--"I have a suspicion that it was some person associated with them--some one who became conscience-stricken. Ah! M'sieur Biddulph, if you only knew the marvellous cunning of that invulnerable gang. Had it not been for that informant, they would still be operating--in open defiance of the police of Europe. Criminal methods, if expert, only fail for want of funds. Are not some of our wealthiest financiers mere criminals who, by dealing in thousands, as other men deal in francs, conceal their criminal methods? Half your successful financiers are merely successful adventurers. The _dossiers_ of some of them, preserved in the police bureaux, would be astounding reading to those who admire them and proclaim them the successful men of to-day--kings of finance they call them!" "You are certainly something of a philosopher," I laughed, compelled to admit the truth of his argument; "but tell me--how is it that you know so much concerning George Harriman, alias Bell, and his antecedents?" CHAPTER EIGHTEEN PROOF POSITIVE