THERE'S not even a wisp of fog now, but some of the London streets which were stalked by Jack the Ripper more than a 100 years ago are still there. Your walk starts at the Whitechapel Underground Station. The building to the left of the station as you emerge was the Whitechapel Working Lads Institute, used for several of the inquests on Jack the Ripper's victims. And at nearby Durward Street, then known as Buck's Row, Mary Nichols, a prostitute in her 40s, known to her friends as ''Polly'', was discovered on August 31, 1888, her throat cut and her head all but severed. She had been disembowelled, a Ripper trademark. Near Hanbury Street is a brewery which was a courtyard where Annie Chapman, nick-named ''Dark Annie'', was murdered eight days later. She had been turned out of her lodgings and needed money for a bed. She suffered the same fate. Continue along Hanbury Street, turn left into Commercial Street and you're at the Ten Bells which has been there since 1753. It's the pub where Dark Annie had her last drink. Around here deserted buildings add to the atmosphere. On the next corner is Christ Church, Spitalfields, designed by Nicholas Hawksmoor and still just as it was when the Ripper claimed his five victims - some say 11. Dorset Street was in those dark days Miller's Court, and at 26 Dorset Street the fifth murder took place. It was the only one of Jack the Ripper's crimes to be committed indoors and he clearly had time to wreak his hell on Mary Kelly. Her body was hardly recognisable. The mutilations had persuaded many that the killer had surgical skills, hence a doctor, maybe a butcher, even a midwife. The search for the killer's identity continues even today, although suggestions that the Royal Family and other society toffs were involved have been shown to be the wildest fiction. Continue on to Crispin Street and turn left. Across the road is the convent where Annie Chapman sometimes stayed. The route now passes through some drab areas. On to Mitre Square, where in the early hours of September 30, 1888, Catherine Eddowes met Jack. Earlier in the evening the local ''bobbies'' who knew her well had found her blind drunk and given her a chance to sleep it off at the police station. She had only 30 minutes left to live when she walked out. Her throat was gashed, her face hacked away and her intestines spread over her. And the horror isn't over yet. Walk to Henriques Street. This is where Elizabeth Stride met Jack on the same night he killed Catherine Eddowes. ''Long Liz'' also had her throat cut. Her body was still warm when they found her. On that very day the same man who had given himself the name Jack the Ripper, sent this postcard to the police: ''I was not codding dear old Boss when I gave you the tip. You'll hear about saucy Jacky's work tomorrow. Double event this time. Number onesquealed a bit. Couldn't finish straight off. Had no time to get ears for police . . . Jack the Ripper.'' He made sure of the ears when he slew Mary Kelly. They never did discover who the Ripper was, but the tour guides aren't complaining. They're coining it in on the trail of death.