Image Transmission and Selenium: Adriano de Paiva and Initial Steps in the XIX Century

Sound transmission, in the form of the telephone, was invented by Alexander Graham Bell et al. in the seventies of the XIX century. Inspired by this development, Adriano de Paiva published in 1878 the idea of the transmission of images at a distance using electricity and selenium. His proposal was based upon earlier work by Jöns Jacob Berzelius, who identified the selenium element in 1817, and of Willoughby Smith, who in 1873 identified a peculiar property of this material—its conductivity dependence upon incident light. The 1878 paper of Adriano de Paiva is the first publication proposing to benefit from the properties of selenium in order to achieve electrical image transmission at a distance and, in the words of the author, enable ubiquity—the transmission of sound and image anywhere in real time. This encyclopedia entry delves into the early steps of electrical image transmission, concisely presenting the protagonists and controversies of scientific priority, and mentioning the impact of those pioneering contributions, still mentioned today, approximately one and a half centuries later.