Primary Sources in American History, Bowdoin Library research guide
HathiTrust contains the digitized collections of some of the nation's great research libraries. Works in the public domain in HathiTrust ("full view") are open to all researchers. Examples:
Healthful living, published by the Battle Creek Food Co., [1927?]
Science and health : with key to the Scriptures, Mary Baker Eddy
A full-text search on: "water cure*" OR hydrotherapy
Archives & Libraries may have online exhibits or digital collections.
Maine Memory Network, Maine Historical Society
Maine Historical Society has materials on medical history, including Dr. Jeremiah Barker's (1752-1835) manuscript history of 18th century diseases in Maine and Dr. Alexander Ramsey's early 19th century anatomical drawings
Finding aid, Medical School of Maine: Historical Records and Files, George J. Mitchell Department of Special Collections & Archives, Bowdoin College Library.
WorldCat. Database contains the holdings of every major library in the U.S. and some in Britain, over 40 million records. Also includes some archival materials.