Hofmann signed 1943 LSD Patent
Albert Hofmann and Arthur Stoll's 1943 patent for the production of LSD - signed by Hofmann and he has also scrawled the structure of LSD. I acquired the patent from the US Patent Office and had Hofmann sign it at one of his 100th birthday symposia. As far as I know, I have the only example in existence (i.e. LSD patent signed by Hofmann).