Electrical demonstrations by Watson included the generation of the charge, right its transmission along a metal rod E resting on a silk bands, and the ignition of spirits of wine in spoon held by the lady, through the man G and his sword. Above, chaff flutters between the plates held by the insulated boy and the grounded girl. Illustration taken from "Expericences et Ovservations, pour servir a l'Explication de la Nature et des Proprietes de l'Electricite" by William Watson, 1748. William Watson (April 3, 1715 - May 10, 1787) was an English physician and scientist. In 1746, he showed that the capacity of the Leyden jar could be increased by coating it inside and out with lead foil. Watson and Benjamin Franklin were allies in both scientific and political matters. This image has been colorized.