Alessandro Volta, man and scientist

4. Research on gases
Volta observed that his pistol could be used to measure the force of the explosion of inflammable airs.
Used like this, the pistol became an eudiometer, an instrument for measuring the quantity of oxygen present in air and therefore its salubrity.
He also made an everlasting lamp using inflammable gas.

The perpetual Lamp

Still in 1776, Volta had the idea of using a long metal wire, insulated from the ground by wooden boards, for conveying an electric signal. In his mind the signal generated in Como by a Leyden jar would be received in Milan where it fired Volta’s pistol. The electric circuit was completed via a series of water courses, from Lake Como to the Canal Port in Milan. As you can readily understand, this idea adumbrated the telegraph.

Illustration, signed by Volta, of the pistol firing at a distance