Subject
5 free books about degeneration, free to read online. Chapter 1 of any book is free, no account needed.
Degeneration
Max Simon Nordau
Degeneracy: Its Causes, Signs and Results
Eugene S. Talbot
The Law of Civilization and Decay: An Essay on History
Brooks Adams
On art and artists
Degeneration: A Chapter in Darwinism
Sir E. Ray (Edwin Ray) Lankester