This black and white photograph shows John Wesley's electricity machine. Like many educated men and women of the 18th century Enlightenment, John Wesley was an enthusiastic believer in the healing properties of electricity. Portable machines such as this one were invented to harness and channel electricity in the treatment of ailments.
In 1747 Wesley wrote a tract, the 'Primitive Physic', a compendium of treatments for many common problems and diseases. In this, he mentions use of 'electrifying' as treatment for a wide range of conditions. Unusually for 18th century London, Wesley offered free electrification for his followers. It is known that Wesley had four electricity machines available for treatment in different locations in London. This is believed to be one of of them.