Read "The Potion of Dreams" at The Eldritch Dark:
This sonnet definitely comes from the strand of Clark Ashton Smith's (CAS) poetry that appeals strongly to me, with an emphasis on the power of dreams, which I choose to extend to the power of the imagination, even if that second element may not be explicitly woven into this particular poem.
What really works here is that strong first line "What occult Circe of the hours of sleep". The reference to the Greek goddess of herbs, magic, and potions provides associations that create a solid foundation before we even get to the second line where CAS gives us "the Cup of Dreams", which he proceeds to fill with richly developed details.
Many poets (and writers in general) incorporate references to mythology in their work, but too often it feels more like a demonstration of erudition than an effective literary device. By using a single direct reference to the Greek myths, CAS keeps his focus and gives the poem a strong footing from the very first line.