Dr. Merryweather, honorary curator of the Whitby Literary and Philosophical Society's Museum, detailed the sensitivity that medicinal leeches displayed in reaction to electrical conditions in the atmosphere.
On 27 February 1851 he gave a nearly three-hour essay to members of the Philosophical Society entitled "Essay explanatory of the Tempest Prognosticator in the building of the Great Exhibition for the Works of Industry of All Nations."[REF] .