How long is it? (word count)
Sounds like a good thing we should make into an audio book for more convenient consumption. I have taken a look around, and don’t see an original source so far for Quincy’s work.
You can find references to it searching for John Quincy Adams 1827 “Essay on Turks”. You might find it at the link below but the publication is over 800 pages
lunt, Joseph (1830), The American Annual Register for the Years 1827-8-9 (New York: E. & G.W. Blunt), 29:267-402, [On-line], http://www.archive.org/stream/p1americanannual29blunuoft