My GGG Grandmother, Mrs. Cornelia (Divine) Cannon, began running
advertisements as early as 1876 as a "Magnetic Physician"
and they continued to run until at least Dec of 1879.
Check out the links below for more on the history of magnetic theory
& the 19th century era which no doubt influenced Cornelia's decision to give it a whirl.
Amylynne (Baker) Murphy