Although Dr. Priest was not listed in the 1877 Grant Co.,IN Atlas, he did publish an article for Rolland Lewis Whitson for his 1914 History of Grant County entitled Medicine and Doctors by Dr. F.A. Priest - the last sentence summing up its contents - "Such has been the advance of medicine in Grant county that from saddle-bags to hospitals has marked the progress of the last half century." Have you read the entire article? This isn't an answer to your query, but it is interesting!