Elmer Paisley:

“The Tune of Seven Towers” from “Pre-Raphaelite Ballads” by William Morris, illust. H.M. O’Kane
(Click for the complete book, via archive.org) 

Sculptures by H.L. Tyler

“The Kingdom of Dreams” suite: Jacob Landau’s illustrations for “Selected Writings of E.T.A. Hoffmann” (University of Chicago Press, 1969)

(source)

“I have been reading Vathek, ‘tis a mad Book to be sure, and written by a mad Author…”- Mrs. Thrale-Piozzi

Just finished reading this book last night. The above is an accurate description.

“Haschisch Hallucinations” (1905) Drug-induced visions by Sidney Sime (source - including the full text of the original article by H.E. Gowers!)

Trippy.

“A Strange Manuscript Found in a Copper Cylinder” (1888) illustrations by Gilbert Gaul (source)