R Austin Freeman 
Dr Thorndyke Intervenes [EPUB ebook] 
classic

Richard Austin Freeman was a British writer of detective stories, mostly featuring the medico-legal forensic investigator Dr. Thorndyke. He claimed to have invented the inverted detective story. Freeman used some of his early experiences as a colonial surgeon in his novels. Many of the Dr. Thorndyke stories involve genuine points of scientific knowledge, from areas such as tropical medicine, metallurgy and toxicology.