[PT031AAB1], Technical Note, Thomas Alva Edison, September 21st, 1888
74 page (221-image) caveat on phonograph; telegraph, and telephone
Chemicals, chemical products, and chemical processes
[PT031AAB-F] Patent Series -- Caveat Files
https://edisondigital.rutgers.edu/document/PT031AAB1
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
Archive.org Viewer, Microfilm Series Reel 113