A vintage medical instrument called the "Singing rheotome". This device would be used to create interruptions in an electrical current to create vibrations that would "sing". Dr. Hutchinson introduced the device in 1892 and claimed that 3 minutes of treatment with the device tuned to the key of C major (450 vibrations per second) would create a brief period of local anesthesia and 15 minutes would have the same effect but possibly lasting for days. This claims were disproven in 1901 and the devices would fall out of use by the end of the decade. This rheotome appears complete with instructions for use still clear and legible. Wooden case is slightly worn on exterior. Lid and case are both numbered "78" on hinged edge. The instrument panel has some signs of use. No batteries are present in bottom drawer with one divider not attached. An interesting device from the turn of the century. See photos. Measures 10.875"W x 8"D x 9"T when closed.