The Venner Crime — John Rhode

The “astute and sharp-spoken” crime-solving professor must find out if a missing man got away with murder (The New York Times).
 
After some initial suspicion, the death of Ernest Venner's wealthy uncle was attributed to natural causes -- a simple infection. But Dr. Lancelot Priestley and his crime-solving companions find it intriguing, to say the least, that as soon as Venner collected his much-needed inheritance, he vanished into the wind.
 
Digging into the disappearance, though, will lead Priestley to some dangerous places, in this suspenseful Golden Age mystery featuring the scientifically minded sleuth . . .