The short story "No-Man's Land" (1899) by
John Buchan has a similar plot to "The Novel of the Black Seal". In both stories a traveller in a remote area encounters a malevolent race of "little people". Buchan was familiar with Machen's writings, suggesting that Machen's story may have been an influence on Buchan's. At least two of the novel's tales, "The Novel of the Black Seal" and "The Novel of the White Powder", influenced the work of
H. P. Lovecraft. In his survey
Supernatural Horror in Literature, Lovecraft suggested that these stories "perhaps represent the highwater mark of Machen's skill as a terror-weaver". "The Novel of the Black Seal" was a model for some of Lovecraft's best-known stories: "
The Call of Cthulhu", "
The Dunwich Horror", and "
The Whisperer in Darkness". The story also bears strong resemblance to Lovecraft's story "
The Lurking Fear", which tells of a deformed humanoid race living in a rural region of the Catskill Mountains. "The Novel of the White Powder", which Lovecraft said "approaches the absolute culmination of loathsome fright", is pointed to as an inspiration for Lovecraft's stories of bodily disintegration, such as "
Cool Air" and "
The Colour Out of Space". Two of
Robert E. Howard's stories,
Worms of the Earth (1932) and
The Little People (1970) were also influenced by "The Novel of the Black Seal". The story "Rx… Death!" in issue 20 of
Tales from the Crypt is an adaptation of "The Novel of the White Powder", except the poisonous "medicine" contains
digestive enzymes rather than a witch's brew. ==Machen's later reflections on the novel==