Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.puppypilgrim
09-22-10, 03:33 PM
He found that using semen was a viable method to produce invisible ink in the field. Agent's name? Mansfield Cumming. You can't make this stuff up.
Source: http://www.boingboing.net/2010/09/22/top-uk-spies-reveale.html
Source: http://www.boingboing.net/2010/09/22/top-uk-spies-reveale.html