AC "Patent Magneto-Electric" Quack Medical Device made by Davis & Kidder for "nervous diseases" (ca. 1865). 

Ari Davis (ca. 1811-1855) was a skilled American craftsman who received two patents in 1854. One of these (#11,415 of August 1) described a magneto-electric machine. While this patent was still in process, Davis sold the patent rights  to Walter Kidder, a physician in Lowell, Massachusetts, allegedly for $4,000. Advertisements soon followed for DAVIS & KIDDER’S PATENT MAGNETO-ELECTRIC MACHINE FOR NERVOUS DISEASES which featured testimonials from three Americans involved with science: Benjamin Silliman at Yale College, Charles G. Page in Washington, D.C., and James R. Chilton, an instrument dealer in New York City. These machines were “MANUFACTURED BY W. KIDDER, Sole Proprietor, whose signature is attached to all genuine Machines.” By 1857, the business was in the hands of William H. Burnap (b. 1825), also of Lowell. And by1865, Burnap was working in New York City and advertising as “Manufacturer of Davis & Kidder’s Electric Machines.”  The label inset to the lid of this machine indicates that the item offered here was made and sold by Burnap in New York.

This example is in a wood box with brass corners and a brass crank handle. The paper label inset into the lid is marked “DAVIS & KIDDER’S / PATENT MAGNETO-ELECTRIC MACHINE / FOR NERVOUS DISEASES” and “PATENTED AUG. 1, 1854” with endorsements from Silliman (at left) and Paige (at right). The text at the bottom reads “Manufactured and sold by W. H. BURNAP, Sole Proprietor, 259 West 27th St., New York, whose signature is attached to all genuine / Machines. All infringements will be prosecuted."

The fully intact label is in excellent condition and has three drawings representing different applications of the device:  (1) chiropractic use on a patient's back (left), (2) a male patient with conducting paddles, one in each hand, likely for nervous disease treatment (center), and (3) a female patient with one conducting paddle in one hand, and the other conducting panel in a tub of water with the patient's foot inside, indicating treatment for some type of foot or leg ailment.    

The device is operated by cranking the brass handle on the front which through gears and two pulleys cause two cylindrical coils on the left of the machine to rotate in front of a large u-shaped permanent magnet in the back of the box. This rotation induces an AC current  (Faraday's law) in the coils and the conducting paddles if the paddles are placed at two points on a patient to complete the electrical circuit so that a low-voltage current can flow.  The conducting paddles in this very early version of the device are hollow metal cylinders connected to wires that attach to connections on the wood box. These cylinders could be gripped by a patient, placed on various parts of a patient's body (i.e. back), or placed in a tub of water where a patient's body part was present, to deliver a mild electrical shock. Note that in this very early example the metal cylinders have the original sponges in the hollow interior which, when wet and placed inside the cylinders, increases the electrical conductivity and flow of current.

The device is complete, functional, and 100% original  Overall the device is in very good condition with a few nicks and scratches on the wood box.