Meanwhile robberies of every description continued to be perpetrated, and Vidocq was more and more in demand. He made it his business to undertake a series of rounds through Paris and the immediate neighborhood, and regularly visited the worst quarters, ever on the alert to discover and check projected crimes. He was taken on by the Prefecture as a salaried agent at the rate of 100 francs per month, with a specially apportioned reward for every arrest, according to its importance. This salary was saddled with a condition that he should produce a certain number of criminals at regular intervals; and his enemies declared that he was capable of any base perfidy in order to make up his required quota of arrests, and that he heartlessly betrayed people, to whom he was under obligation--as in the case of the tanner with whom he lodged, and whom he secretly denounced as a fabricator of false money. A medical man who attended him was implicated in this charge, and both were arrested and sent to _travaux forcés_. He was accused also of instigating crimes of which he gave information, and saw to it that their perpetrators were taken in the act or with clear evidence. It may be claimed that in criminal matters all is fair that may conduce to arrest, although this savors of the argument that “the end justifies the means.” Vidocq, at least, had no scruples, and would lay traps and be guilty of any treachery in order to bring an offender to justice. He had no reason to be proud of the manner in which he routed out the house of Madame Noel--commonly known as the mother of the robbers--which was a certain refuge and receptacle, where they could always find shelter and assistance. Mother Noel provided for all their wants. She always knew where they could find work, each one on his particular “lay.” She had blank passports on hand, and could fabricate papers for any one in want of them. Vidocq visited the house and acted the part of a convict recently escaped, still bearing the marks of his chains, with closely cropped hair, worn out and wearied, his feet lacerated, his whole air that of one hunted and proscribed. He won the woman’s sympathy instantly, and was made warmly welcome. He was given a bath, his wounds were dressed and he was put to bed in a very private room. He soon wormed himself into her confidence, gained all the knowledge he required, and eventually broke up this refuge and receptacle so useful to the thieves of Paris.