Arthur Gask 
The Poisoned Goblet [EPUB ebook] 

“We may say what we will, Mr. Larose, ” remarked the thin scholarly looking man in a rather regretful tone, “but evil in a jeweled setting is less repugnant to the human mind, than when met with in sordid surroundings, and crime among the well-to-do is more intriguing than breaches of the law among the lower classes.”
“That is quite true, Mr. Jones, ” replied the smiling young man opposite to him. “Wrong doing amongst educated and refined people seems always to have more element of adventure behind it”—he smiled—“and certainly the smells of Mayfair are much to be preferred to those of Bethnal Green.”