Improved The Davis & Kidder Patent magneto-electric machine for nervous diseases 19th century retailed by William Hume of Edinburgh in original case and complete with brass tubes and turning handle, original paper instructions to inner lid. Mechanism seems to be working, but not fully tested. In 1854, manufacturer W.H. Burnap produced a well-known electrotherapy device that was purchased by the general consumer as well as some physicians and hospitals: The Davis & Kidder Patent Magneto-Electric Machine for Nervous Diseases. Electricity was produced using the large magnet and the strength of the electric shock was controlled by how fast the crank was turned. The operator of this electromagnetic generator would place handles in the patient’s hands or elsewhere on the patient’s body and then turn a crank to deliver a ‘mild’ alternating current to the patient. The force of the current depended upon the speed with which the crank was turned. Although little more than medical quackery, thousands of these machines were made.