Letter, from Robert Hunt to Sir John Herschel, dated at Falmouth Autograph letter signed by sender. Has been working at [L. F.] Moser's experiments and believes he is wrong in considering latent light as the agent that produces the photographic image. Read a paper last evening on the subject, which will be printed. Has been producing images by the action of heat and electricity and proposes to call this process Thermography. 9 November 1842