Supernatural Detectives 5: The Colour-Criminologist / From Whose Bourne

The Colour-Criminologist: Dr. John Durston uses colour mentation to study chromatic vibrations, allowing him, among other things, to see visions of events elsewhere. Miss Dalrymple joins him in his research, leading to strange adventures. These stories were first published in 1917 as The Rainbow Mystery: Chronicles of a Colour-Criminologist, by William Le Queux (1864-1927).

From Whose Bourne: William Brenton is dead. Was it murder? If so, was it his wife, Alice? The police think so. A detective is needed, but the only one pursuing the inquiry is William himself. As a ghostly investigator, William finds he needs help from both sides of the veil. From Whose Bourne by Robert Barr (1849-1912) was published in 1896.